Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1 | :mod:`os` --- Miscellaneous operating system interfaces |
| 2 | ======================================================= |
| 3 | |
| 4 | .. module:: os |
| 5 | :synopsis: Miscellaneous operating system interfaces. |
| 6 | |
| 7 | |
Christian Heimes | a62da1d | 2008-01-12 19:39:10 +0000 | [diff] [blame] | 8 | This module provides a portable way of using operating system dependent |
| 9 | functionality. If you just want to read or write a file see :func:`open`, if |
| 10 | you want to manipulate paths, see the :mod:`os.path` module, and if you want to |
| 11 | read all the lines in all the files on the command line see the :mod:`fileinput` |
| 12 | module. For creating temporary files and directories see the :mod:`tempfile` |
| 13 | module, and for high-level file and directory handling see the :mod:`shutil` |
| 14 | module. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 15 | |
Benjamin Peterson | 1baf465 | 2009-12-31 03:11:23 +0000 | [diff] [blame] | 16 | Notes on the availability of these functions: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 17 | |
Benjamin Peterson | 1baf465 | 2009-12-31 03:11:23 +0000 | [diff] [blame] | 18 | * The design of all built-in operating system dependent modules of Python is |
| 19 | such that as long as the same functionality is available, it uses the same |
| 20 | interface; for example, the function ``os.stat(path)`` returns stat |
| 21 | information about *path* in the same format (which happens to have originated |
| 22 | with the POSIX interface). |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 23 | |
Benjamin Peterson | 1baf465 | 2009-12-31 03:11:23 +0000 | [diff] [blame] | 24 | * Extensions peculiar to a particular operating system are also available |
| 25 | through the :mod:`os` module, but using them is of course a threat to |
| 26 | portability. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 27 | |
Benjamin Peterson | 1baf465 | 2009-12-31 03:11:23 +0000 | [diff] [blame] | 28 | * All functions accepting path or file names accept both bytes and string |
| 29 | objects, and result in an object of the same type, if a path or file name is |
| 30 | returned. |
Georg Brandl | 76e5538 | 2008-10-08 16:34:57 +0000 | [diff] [blame] | 31 | |
Benjamin Peterson | 1baf465 | 2009-12-31 03:11:23 +0000 | [diff] [blame] | 32 | * An "Availability: Unix" note means that this function is commonly found on |
| 33 | Unix systems. It does not make any claims about its existence on a specific |
| 34 | operating system. |
| 35 | |
| 36 | * If not separately noted, all functions that claim "Availability: Unix" are |
| 37 | supported on Mac OS X, which builds on a Unix core. |
| 38 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 39 | .. Availability notes get their own line and occur at the end of the function |
| 40 | .. documentation. |
| 41 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 42 | .. note:: |
| 43 | |
Christian Heimes | a62da1d | 2008-01-12 19:39:10 +0000 | [diff] [blame] | 44 | All functions in this module raise :exc:`OSError` in the case of invalid or |
| 45 | inaccessible file names and paths, or other arguments that have the correct |
| 46 | type, but are not accepted by the operating system. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 47 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 48 | .. exception:: error |
| 49 | |
Christian Heimes | a62da1d | 2008-01-12 19:39:10 +0000 | [diff] [blame] | 50 | An alias for the built-in :exc:`OSError` exception. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 51 | |
| 52 | |
| 53 | .. data:: name |
| 54 | |
Benjamin Peterson | 1baf465 | 2009-12-31 03:11:23 +0000 | [diff] [blame] | 55 | The name of the operating system dependent module imported. The following |
Ned Deily | 5c86701 | 2014-06-26 23:40:06 -0700 | [diff] [blame] | 56 | names have currently been registered: ``'posix'``, ``'nt'``, |
Jesus Cea | f6c2e89 | 2012-10-05 01:11:10 +0200 | [diff] [blame] | 57 | ``'ce'``, ``'java'``. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 58 | |
Antoine Pitrou | a83cdaa | 2011-07-09 15:54:23 +0200 | [diff] [blame] | 59 | .. seealso:: |
| 60 | :attr:`sys.platform` has a finer granularity. :func:`os.uname` gives |
| 61 | system-dependent version information. |
| 62 | |
| 63 | The :mod:`platform` module provides detailed checks for the |
| 64 | system's identity. |
| 65 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 66 | |
Martin v. Löwis | 011e842 | 2009-05-05 04:43:17 +0000 | [diff] [blame] | 67 | .. _os-filenames: |
Victor Stinner | 6bfd854 | 2014-06-19 12:50:27 +0200 | [diff] [blame] | 68 | .. _filesystem-encoding: |
Martin v. Löwis | 011e842 | 2009-05-05 04:43:17 +0000 | [diff] [blame] | 69 | |
| 70 | File Names, Command Line Arguments, and Environment Variables |
| 71 | ------------------------------------------------------------- |
| 72 | |
Georg Brandl | 67b21b7 | 2010-08-17 15:07:14 +0000 | [diff] [blame] | 73 | In Python, file names, command line arguments, and environment variables are |
| 74 | represented using the string type. On some systems, decoding these strings to |
| 75 | and from bytes is necessary before passing them to the operating system. Python |
| 76 | uses the file system encoding to perform this conversion (see |
| 77 | :func:`sys.getfilesystemencoding`). |
Martin v. Löwis | 011e842 | 2009-05-05 04:43:17 +0000 | [diff] [blame] | 78 | |
| 79 | .. versionchanged:: 3.1 |
Georg Brandl | 67b21b7 | 2010-08-17 15:07:14 +0000 | [diff] [blame] | 80 | On some systems, conversion using the file system encoding may fail. In this |
| 81 | case, Python uses the ``surrogateescape`` encoding error handler, which means |
| 82 | that undecodable bytes are replaced by a Unicode character U+DCxx on |
| 83 | decoding, and these are again translated to the original byte on encoding. |
Martin v. Löwis | 011e842 | 2009-05-05 04:43:17 +0000 | [diff] [blame] | 84 | |
| 85 | |
Georg Brandl | 67b21b7 | 2010-08-17 15:07:14 +0000 | [diff] [blame] | 86 | The file system encoding must guarantee to successfully decode all bytes |
| 87 | below 128. If the file system encoding fails to provide this guarantee, API |
| 88 | functions may raise UnicodeErrors. |
Martin v. Löwis | 011e842 | 2009-05-05 04:43:17 +0000 | [diff] [blame] | 89 | |
| 90 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 91 | .. _os-procinfo: |
| 92 | |
| 93 | Process Parameters |
| 94 | ------------------ |
| 95 | |
| 96 | These functions and data items provide information and operate on the current |
| 97 | process and user. |
| 98 | |
| 99 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 100 | .. function:: ctermid() |
| 101 | |
| 102 | Return the filename corresponding to the controlling terminal of the process. |
| 103 | |
| 104 | Availability: Unix. |
| 105 | |
| 106 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 107 | .. data:: environ |
| 108 | |
Chris Jerdonek | 11f3f17 | 2012-11-03 12:05:55 -0700 | [diff] [blame] | 109 | A :term:`mapping` object representing the string environment. For example, |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 110 | ``environ['HOME']`` is the pathname of your home directory (on some platforms), |
| 111 | and is equivalent to ``getenv("HOME")`` in C. |
| 112 | |
| 113 | This mapping is captured the first time the :mod:`os` module is imported, |
| 114 | typically during Python startup as part of processing :file:`site.py`. Changes |
| 115 | to the environment made after this time are not reflected in ``os.environ``, |
| 116 | except for changes made by modifying ``os.environ`` directly. |
| 117 | |
| 118 | If the platform supports the :func:`putenv` function, this mapping may be used |
| 119 | to modify the environment as well as query the environment. :func:`putenv` will |
| 120 | be called automatically when the mapping is modified. |
| 121 | |
Victor Stinner | 84ae118 | 2010-05-06 22:05:07 +0000 | [diff] [blame] | 122 | On Unix, keys and values use :func:`sys.getfilesystemencoding` and |
| 123 | ``'surrogateescape'`` error handler. Use :data:`environb` if you would like |
| 124 | to use a different encoding. |
| 125 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 126 | .. note:: |
| 127 | |
| 128 | Calling :func:`putenv` directly does not change ``os.environ``, so it's better |
| 129 | to modify ``os.environ``. |
| 130 | |
| 131 | .. note:: |
| 132 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 133 | On some platforms, including FreeBSD and Mac OS X, setting ``environ`` may |
| 134 | cause memory leaks. Refer to the system documentation for |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 135 | :c:func:`putenv`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 136 | |
| 137 | If :func:`putenv` is not provided, a modified copy of this mapping may be |
| 138 | passed to the appropriate process-creation functions to cause child processes |
| 139 | to use a modified environment. |
| 140 | |
Georg Brandl | 9afde1c | 2007-11-01 20:32:30 +0000 | [diff] [blame] | 141 | If the platform supports the :func:`unsetenv` function, you can delete items in |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 142 | this mapping to unset environment variables. :func:`unsetenv` will be called |
Georg Brandl | 9afde1c | 2007-11-01 20:32:30 +0000 | [diff] [blame] | 143 | automatically when an item is deleted from ``os.environ``, and when |
| 144 | one of the :meth:`pop` or :meth:`clear` methods is called. |
| 145 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 146 | |
Victor Stinner | 84ae118 | 2010-05-06 22:05:07 +0000 | [diff] [blame] | 147 | .. data:: environb |
| 148 | |
Chris Jerdonek | 11f3f17 | 2012-11-03 12:05:55 -0700 | [diff] [blame] | 149 | Bytes version of :data:`environ`: a :term:`mapping` object representing the |
Victor Stinner | 84ae118 | 2010-05-06 22:05:07 +0000 | [diff] [blame] | 150 | environment as byte strings. :data:`environ` and :data:`environb` are |
| 151 | synchronized (modify :data:`environb` updates :data:`environ`, and vice |
| 152 | versa). |
| 153 | |
Victor Stinner | b745a74 | 2010-05-18 17:17:23 +0000 | [diff] [blame] | 154 | :data:`environb` is only available if :data:`supports_bytes_environ` is |
| 155 | True. |
Victor Stinner | 84ae118 | 2010-05-06 22:05:07 +0000 | [diff] [blame] | 156 | |
Benjamin Peterson | 662c74f | 2010-05-06 22:09:03 +0000 | [diff] [blame] | 157 | .. versionadded:: 3.2 |
| 158 | |
Victor Stinner | 84ae118 | 2010-05-06 22:05:07 +0000 | [diff] [blame] | 159 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 160 | .. function:: chdir(path) |
| 161 | fchdir(fd) |
| 162 | getcwd() |
| 163 | :noindex: |
| 164 | |
| 165 | These functions are described in :ref:`os-file-dir`. |
| 166 | |
| 167 | |
Victor Stinner | e8d5145 | 2010-08-19 01:05:19 +0000 | [diff] [blame] | 168 | .. function:: fsencode(filename) |
Victor Stinner | 449c466 | 2010-05-08 11:10:09 +0000 | [diff] [blame] | 169 | |
Victor Stinner | e8d5145 | 2010-08-19 01:05:19 +0000 | [diff] [blame] | 170 | Encode *filename* to the filesystem encoding with ``'surrogateescape'`` |
Victor Stinner | 62165d6 | 2010-10-09 10:34:37 +0000 | [diff] [blame] | 171 | error handler, or ``'strict'`` on Windows; return :class:`bytes` unchanged. |
Victor Stinner | e8d5145 | 2010-08-19 01:05:19 +0000 | [diff] [blame] | 172 | |
Antoine Pitrou | a305ca7 | 2010-09-25 22:12:00 +0000 | [diff] [blame] | 173 | :func:`fsdecode` is the reverse function. |
Victor Stinner | e8d5145 | 2010-08-19 01:05:19 +0000 | [diff] [blame] | 174 | |
| 175 | .. versionadded:: 3.2 |
| 176 | |
| 177 | |
| 178 | .. function:: fsdecode(filename) |
| 179 | |
| 180 | Decode *filename* from the filesystem encoding with ``'surrogateescape'`` |
Victor Stinner | 62165d6 | 2010-10-09 10:34:37 +0000 | [diff] [blame] | 181 | error handler, or ``'strict'`` on Windows; return :class:`str` unchanged. |
Victor Stinner | e8d5145 | 2010-08-19 01:05:19 +0000 | [diff] [blame] | 182 | |
| 183 | :func:`fsencode` is the reverse function. |
Victor Stinner | 449c466 | 2010-05-08 11:10:09 +0000 | [diff] [blame] | 184 | |
| 185 | .. versionadded:: 3.2 |
| 186 | |
| 187 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 188 | .. function:: getenv(key, default=None) |
| 189 | |
| 190 | Return the value of the environment variable *key* if it exists, or |
| 191 | *default* if it doesn't. *key*, *default* and the result are str. |
| 192 | |
| 193 | On Unix, keys and values are decoded with :func:`sys.getfilesystemencoding` |
| 194 | and ``'surrogateescape'`` error handler. Use :func:`os.getenvb` if you |
| 195 | would like to use a different encoding. |
| 196 | |
| 197 | Availability: most flavors of Unix, Windows. |
| 198 | |
| 199 | |
| 200 | .. function:: getenvb(key, default=None) |
| 201 | |
| 202 | Return the value of the environment variable *key* if it exists, or |
| 203 | *default* if it doesn't. *key*, *default* and the result are bytes. |
| 204 | |
| 205 | Availability: most flavors of Unix. |
| 206 | |
| 207 | .. versionadded:: 3.2 |
| 208 | |
| 209 | |
Gregory P. Smith | b6e8c7e | 2010-02-27 07:22:22 +0000 | [diff] [blame] | 210 | .. function:: get_exec_path(env=None) |
| 211 | |
| 212 | Returns the list of directories that will be searched for a named |
| 213 | executable, similar to a shell, when launching a process. |
| 214 | *env*, when specified, should be an environment variable dictionary |
| 215 | to lookup the PATH in. |
| 216 | By default, when *env* is None, :data:`environ` is used. |
| 217 | |
| 218 | .. versionadded:: 3.2 |
| 219 | |
| 220 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 221 | .. function:: getegid() |
| 222 | |
| 223 | Return the effective group id of the current process. This corresponds to the |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 224 | "set id" bit on the file being executed in the current process. |
| 225 | |
| 226 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 227 | |
| 228 | |
| 229 | .. function:: geteuid() |
| 230 | |
| 231 | .. index:: single: user; effective id |
| 232 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 233 | Return the current process's effective user id. |
| 234 | |
| 235 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 236 | |
| 237 | |
| 238 | .. function:: getgid() |
| 239 | |
| 240 | .. index:: single: process; group |
| 241 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 242 | Return the real group id of the current process. |
| 243 | |
| 244 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 245 | |
| 246 | |
Ross Lagerwall | b0ae53d | 2011-06-10 07:30:30 +0200 | [diff] [blame] | 247 | .. function:: getgrouplist(user, group) |
| 248 | |
| 249 | Return list of group ids that *user* belongs to. If *group* is not in the |
| 250 | list, it is included; typically, *group* is specified as the group ID |
| 251 | field from the password record for *user*. |
| 252 | |
| 253 | Availability: Unix. |
| 254 | |
| 255 | .. versionadded:: 3.3 |
| 256 | |
| 257 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 258 | .. function:: getgroups() |
| 259 | |
| 260 | Return list of supplemental group ids associated with the current process. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 261 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 262 | Availability: Unix. |
| 263 | |
Larry Hastings | 3732ed2 | 2014-03-15 21:13:56 -0700 | [diff] [blame] | 264 | .. note:: |
| 265 | |
| 266 | On Mac OS X, :func:`getgroups` behavior differs somewhat from |
Ned Deily | 2e20968 | 2012-04-30 11:14:02 -0700 | [diff] [blame] | 267 | other Unix platforms. If the Python interpreter was built with a |
| 268 | deployment target of :const:`10.5` or earlier, :func:`getgroups` returns |
| 269 | the list of effective group ids associated with the current user process; |
| 270 | this list is limited to a system-defined number of entries, typically 16, |
| 271 | and may be modified by calls to :func:`setgroups` if suitably privileged. |
| 272 | If built with a deployment target greater than :const:`10.5`, |
| 273 | :func:`getgroups` returns the current group access list for the user |
| 274 | associated with the effective user id of the process; the group access |
| 275 | list may change over the lifetime of the process, it is not affected by |
| 276 | calls to :func:`setgroups`, and its length is not limited to 16. The |
| 277 | deployment target value, :const:`MACOSX_DEPLOYMENT_TARGET`, can be |
| 278 | obtained with :func:`sysconfig.get_config_var`. |
| 279 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 280 | |
| 281 | .. function:: getlogin() |
| 282 | |
| 283 | Return the name of the user logged in on the controlling terminal of the |
Benjamin Peterson | e218bcb | 2014-08-30 21:04:15 -0400 | [diff] [blame] | 284 | process. For most purposes, it is more useful to use the environment |
| 285 | variables :envvar:`LOGNAME` or :envvar:`USERNAME` to find out who the user |
| 286 | is, or ``pwd.getpwuid(os.getuid())[0]`` to get the login name of the current |
| 287 | real user id. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 288 | |
Brian Curtin | e8e4b3b | 2010-09-23 20:04:14 +0000 | [diff] [blame] | 289 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 290 | |
| 291 | |
| 292 | .. function:: getpgid(pid) |
| 293 | |
| 294 | Return the process group id of the process with process id *pid*. If *pid* is 0, |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 295 | the process group id of the current process is returned. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 296 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 297 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 298 | |
| 299 | .. function:: getpgrp() |
| 300 | |
| 301 | .. index:: single: process; group |
| 302 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 303 | Return the id of the current process group. |
| 304 | |
| 305 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 306 | |
| 307 | |
| 308 | .. function:: getpid() |
| 309 | |
| 310 | .. index:: single: process; id |
| 311 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 312 | Return the current process id. |
| 313 | |
| 314 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 315 | |
| 316 | |
| 317 | .. function:: getppid() |
| 318 | |
| 319 | .. index:: single: process; id of parent |
| 320 | |
Amaury Forgeot d'Arc | 4b6fdf3 | 2010-09-07 21:31:17 +0000 | [diff] [blame] | 321 | Return the parent's process id. When the parent process has exited, on Unix |
| 322 | the id returned is the one of the init process (1), on Windows it is still |
| 323 | the same id, which may be already reused by another process. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 324 | |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 325 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 326 | |
Amaury Forgeot d'Arc | 4b6fdf3 | 2010-09-07 21:31:17 +0000 | [diff] [blame] | 327 | .. versionchanged:: 3.2 |
| 328 | Added support for Windows. |
Georg Brandl | 1b83a45 | 2009-11-28 11:12:26 +0000 | [diff] [blame] | 329 | |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 330 | |
Giampaolo Rodolà | 18e8bcb | 2011-02-25 20:57:54 +0000 | [diff] [blame] | 331 | .. function:: getpriority(which, who) |
| 332 | |
| 333 | .. index:: single: process; scheduling priority |
| 334 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 335 | Get program scheduling priority. The value *which* is one of |
Giampaolo Rodolà | 18e8bcb | 2011-02-25 20:57:54 +0000 | [diff] [blame] | 336 | :const:`PRIO_PROCESS`, :const:`PRIO_PGRP`, or :const:`PRIO_USER`, and *who* |
| 337 | is interpreted relative to *which* (a process identifier for |
| 338 | :const:`PRIO_PROCESS`, process group identifier for :const:`PRIO_PGRP`, and a |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 339 | user ID for :const:`PRIO_USER`). A zero value for *who* denotes |
Giampaolo Rodolà | 18e8bcb | 2011-02-25 20:57:54 +0000 | [diff] [blame] | 340 | (respectively) the calling process, the process group of the calling process, |
| 341 | or the real user ID of the calling process. |
| 342 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 343 | Availability: Unix. |
Giampaolo Rodolà | 18e8bcb | 2011-02-25 20:57:54 +0000 | [diff] [blame] | 344 | |
| 345 | .. versionadded:: 3.3 |
| 346 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 347 | |
| 348 | .. data:: PRIO_PROCESS |
| 349 | PRIO_PGRP |
| 350 | PRIO_USER |
| 351 | |
| 352 | Parameters for the :func:`getpriority` and :func:`setpriority` functions. |
| 353 | |
| 354 | Availability: Unix. |
| 355 | |
| 356 | .. versionadded:: 3.3 |
| 357 | |
| 358 | |
Gregory P. Smith | cf02c6a | 2009-11-27 17:54:17 +0000 | [diff] [blame] | 359 | .. function:: getresuid() |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 360 | |
| 361 | Return a tuple (ruid, euid, suid) denoting the current process's |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 362 | real, effective, and saved user ids. |
| 363 | |
| 364 | Availability: Unix. |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 365 | |
Georg Brandl | 1b83a45 | 2009-11-28 11:12:26 +0000 | [diff] [blame] | 366 | .. versionadded:: 3.2 |
| 367 | |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 368 | |
Gregory P. Smith | cf02c6a | 2009-11-27 17:54:17 +0000 | [diff] [blame] | 369 | .. function:: getresgid() |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 370 | |
| 371 | Return a tuple (rgid, egid, sgid) denoting the current process's |
Georg Brandl | a9b51d2 | 2010-09-05 17:07:12 +0000 | [diff] [blame] | 372 | real, effective, and saved group ids. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 373 | |
| 374 | Availability: Unix. |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 375 | |
Georg Brandl | 1b83a45 | 2009-11-28 11:12:26 +0000 | [diff] [blame] | 376 | .. versionadded:: 3.2 |
| 377 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 378 | |
| 379 | .. function:: getuid() |
| 380 | |
| 381 | .. index:: single: user; id |
| 382 | |
Benjamin Peterson | 4bb09c8 | 2014-06-07 13:50:34 -0700 | [diff] [blame] | 383 | Return the current process's real user id. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 384 | |
| 385 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 386 | |
| 387 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 388 | .. function:: initgroups(username, gid) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 389 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 390 | Call the system initgroups() to initialize the group access list with all of |
| 391 | the groups of which the specified username is a member, plus the specified |
| 392 | group id. |
Giampaolo Rodolà | 18e8bcb | 2011-02-25 20:57:54 +0000 | [diff] [blame] | 393 | |
| 394 | Availability: Unix. |
| 395 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 396 | .. versionadded:: 3.2 |
| 397 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 398 | |
Georg Brandl | 1824415 | 2009-09-02 20:34:52 +0000 | [diff] [blame] | 399 | .. function:: putenv(key, value) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 400 | |
| 401 | .. index:: single: environment variables; setting |
| 402 | |
Georg Brandl | 1824415 | 2009-09-02 20:34:52 +0000 | [diff] [blame] | 403 | Set the environment variable named *key* to the string *value*. Such |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 404 | changes to the environment affect subprocesses started with :func:`os.system`, |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 405 | :func:`popen` or :func:`fork` and :func:`execv`. |
| 406 | |
| 407 | Availability: most flavors of Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 408 | |
| 409 | .. note:: |
| 410 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 411 | On some platforms, including FreeBSD and Mac OS X, setting ``environ`` may |
| 412 | cause memory leaks. Refer to the system documentation for putenv. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 413 | |
| 414 | When :func:`putenv` is supported, assignments to items in ``os.environ`` are |
| 415 | automatically translated into corresponding calls to :func:`putenv`; however, |
| 416 | calls to :func:`putenv` don't update ``os.environ``, so it is actually |
| 417 | preferable to assign to items of ``os.environ``. |
| 418 | |
| 419 | |
| 420 | .. function:: setegid(egid) |
| 421 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 422 | Set the current process's effective group id. |
| 423 | |
| 424 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 425 | |
| 426 | |
| 427 | .. function:: seteuid(euid) |
| 428 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 429 | Set the current process's effective user id. |
| 430 | |
| 431 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 432 | |
| 433 | |
| 434 | .. function:: setgid(gid) |
| 435 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 436 | Set the current process' group id. |
| 437 | |
| 438 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 439 | |
| 440 | |
| 441 | .. function:: setgroups(groups) |
| 442 | |
| 443 | Set the list of supplemental group ids associated with the current process to |
| 444 | *groups*. *groups* must be a sequence, and each element must be an integer |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 445 | identifying a group. This operation is typically available only to the superuser. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 446 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 447 | Availability: Unix. |
| 448 | |
Ned Deily | 2e20968 | 2012-04-30 11:14:02 -0700 | [diff] [blame] | 449 | .. note:: On Mac OS X, the length of *groups* may not exceed the |
| 450 | system-defined maximum number of effective group ids, typically 16. |
| 451 | See the documentation for :func:`getgroups` for cases where it may not |
| 452 | return the same group list set by calling setgroups(). |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 453 | |
| 454 | .. function:: setpgrp() |
| 455 | |
Andrew Svetlov | a2fe334 | 2012-08-11 21:14:08 +0300 | [diff] [blame] | 456 | Call the system call :c:func:`setpgrp` or ``setpgrp(0, 0)`` depending on |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 457 | which version is implemented (if any). See the Unix manual for the semantics. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 458 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 459 | Availability: Unix. |
| 460 | |
| 461 | |
| 462 | .. function:: setpgid(pid, pgrp) |
| 463 | |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 464 | Call the system call :c:func:`setpgid` to set the process group id of the |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 465 | process with id *pid* to the process group with id *pgrp*. See the Unix manual |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 466 | for the semantics. |
| 467 | |
| 468 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 469 | |
| 470 | |
Giampaolo Rodolà | 18e8bcb | 2011-02-25 20:57:54 +0000 | [diff] [blame] | 471 | .. function:: setpriority(which, who, priority) |
| 472 | |
| 473 | .. index:: single: process; scheduling priority |
| 474 | |
| 475 | Set program scheduling priority. The value *which* is one of |
| 476 | :const:`PRIO_PROCESS`, :const:`PRIO_PGRP`, or :const:`PRIO_USER`, and *who* |
| 477 | is interpreted relative to *which* (a process identifier for |
| 478 | :const:`PRIO_PROCESS`, process group identifier for :const:`PRIO_PGRP`, and a |
| 479 | user ID for :const:`PRIO_USER`). A zero value for *who* denotes |
| 480 | (respectively) the calling process, the process group of the calling process, |
| 481 | or the real user ID of the calling process. |
| 482 | *priority* is a value in the range -20 to 19. The default priority is 0; |
| 483 | lower priorities cause more favorable scheduling. |
| 484 | |
| 485 | Availability: Unix |
| 486 | |
| 487 | .. versionadded:: 3.3 |
| 488 | |
| 489 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 490 | .. function:: setregid(rgid, egid) |
| 491 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 492 | Set the current process's real and effective group ids. |
| 493 | |
| 494 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 495 | |
Georg Brandl | 1b83a45 | 2009-11-28 11:12:26 +0000 | [diff] [blame] | 496 | |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 497 | .. function:: setresgid(rgid, egid, sgid) |
| 498 | |
| 499 | Set the current process's real, effective, and saved group ids. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 500 | |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 501 | Availability: Unix. |
| 502 | |
Georg Brandl | 1b83a45 | 2009-11-28 11:12:26 +0000 | [diff] [blame] | 503 | .. versionadded:: 3.2 |
| 504 | |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 505 | |
| 506 | .. function:: setresuid(ruid, euid, suid) |
| 507 | |
| 508 | Set the current process's real, effective, and saved user ids. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 509 | |
Georg Brandl | 6faee4e | 2010-09-21 14:48:28 +0000 | [diff] [blame] | 510 | Availability: Unix. |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 511 | |
Georg Brandl | 1b83a45 | 2009-11-28 11:12:26 +0000 | [diff] [blame] | 512 | .. versionadded:: 3.2 |
| 513 | |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 514 | |
| 515 | .. function:: setreuid(ruid, euid) |
| 516 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 517 | Set the current process's real and effective user ids. |
| 518 | |
| 519 | Availability: Unix. |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 520 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 521 | |
| 522 | .. function:: getsid(pid) |
| 523 | |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 524 | Call the system call :c:func:`getsid`. See the Unix manual for the semantics. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 525 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 526 | Availability: Unix. |
| 527 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 528 | |
| 529 | .. function:: setsid() |
| 530 | |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 531 | Call the system call :c:func:`setsid`. See the Unix manual for the semantics. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 532 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 533 | Availability: Unix. |
| 534 | |
| 535 | |
| 536 | .. function:: setuid(uid) |
| 537 | |
| 538 | .. index:: single: user; id, setting |
| 539 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 540 | Set the current process's user id. |
| 541 | |
| 542 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 543 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 544 | |
Christian Heimes | 5b5e81c | 2007-12-31 16:14:33 +0000 | [diff] [blame] | 545 | .. placed in this section since it relates to errno.... a little weak |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 546 | .. function:: strerror(code) |
| 547 | |
| 548 | Return the error message corresponding to the error code in *code*. |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 549 | On platforms where :c:func:`strerror` returns ``NULL`` when given an unknown |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 550 | error number, :exc:`ValueError` is raised. |
| 551 | |
| 552 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 553 | |
| 554 | |
Victor Stinner | b745a74 | 2010-05-18 17:17:23 +0000 | [diff] [blame] | 555 | .. data:: supports_bytes_environ |
| 556 | |
Serhiy Storchaka | fbc1c26 | 2013-11-29 12:17:13 +0200 | [diff] [blame] | 557 | ``True`` if the native OS type of the environment is bytes (eg. ``False`` on |
Victor Stinner | b745a74 | 2010-05-18 17:17:23 +0000 | [diff] [blame] | 558 | Windows). |
| 559 | |
Victor Stinner | 8fddc9e | 2010-05-18 17:24:09 +0000 | [diff] [blame] | 560 | .. versionadded:: 3.2 |
| 561 | |
Victor Stinner | b745a74 | 2010-05-18 17:17:23 +0000 | [diff] [blame] | 562 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 563 | .. function:: umask(mask) |
| 564 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 565 | Set the current numeric umask and return the previous umask. |
| 566 | |
| 567 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 568 | |
| 569 | |
| 570 | .. function:: uname() |
| 571 | |
| 572 | .. index:: |
| 573 | single: gethostname() (in module socket) |
| 574 | single: gethostbyaddr() (in module socket) |
| 575 | |
Larry Hastings | 605a62d | 2012-06-24 04:33:36 -0700 | [diff] [blame] | 576 | Returns information identifying the current operating system. |
| 577 | The return value is an object with five attributes: |
| 578 | |
| 579 | * :attr:`sysname` - operating system name |
| 580 | * :attr:`nodename` - name of machine on network (implementation-defined) |
| 581 | * :attr:`release` - operating system release |
| 582 | * :attr:`version` - operating system version |
| 583 | * :attr:`machine` - hardware identifier |
| 584 | |
| 585 | For backwards compatibility, this object is also iterable, behaving |
| 586 | like a five-tuple containing :attr:`sysname`, :attr:`nodename`, |
| 587 | :attr:`release`, :attr:`version`, and :attr:`machine` |
| 588 | in that order. |
| 589 | |
| 590 | Some systems truncate :attr:`nodename` to 8 characters or to the |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 591 | leading component; a better way to get the hostname is |
| 592 | :func:`socket.gethostname` or even |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 593 | ``socket.gethostbyaddr(socket.gethostname())``. |
| 594 | |
| 595 | Availability: recent flavors of Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 596 | |
Larry Hastings | 605a62d | 2012-06-24 04:33:36 -0700 | [diff] [blame] | 597 | .. versionchanged:: 3.3 |
| 598 | Return type changed from a tuple to a tuple-like object |
| 599 | with named attributes. |
| 600 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 601 | |
Georg Brandl | 1824415 | 2009-09-02 20:34:52 +0000 | [diff] [blame] | 602 | .. function:: unsetenv(key) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 603 | |
| 604 | .. index:: single: environment variables; deleting |
| 605 | |
Georg Brandl | 1824415 | 2009-09-02 20:34:52 +0000 | [diff] [blame] | 606 | Unset (delete) the environment variable named *key*. Such changes to the |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 607 | environment affect subprocesses started with :func:`os.system`, :func:`popen` or |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 608 | :func:`fork` and :func:`execv`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 609 | |
| 610 | When :func:`unsetenv` is supported, deletion of items in ``os.environ`` is |
| 611 | automatically translated into a corresponding call to :func:`unsetenv`; however, |
| 612 | calls to :func:`unsetenv` don't update ``os.environ``, so it is actually |
| 613 | preferable to delete items of ``os.environ``. |
| 614 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 615 | Availability: most flavors of Unix, Windows. |
| 616 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 617 | |
| 618 | .. _os-newstreams: |
| 619 | |
| 620 | File Object Creation |
| 621 | -------------------- |
| 622 | |
Georg Brandl | a570e98 | 2012-06-24 13:26:22 +0200 | [diff] [blame] | 623 | This function creates new :term:`file objects <file object>`. (See also |
Georg Brandl | b2462e2 | 2012-06-24 13:24:56 +0200 | [diff] [blame] | 624 | :func:`~os.open` for opening file descriptors.) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 625 | |
| 626 | |
Petri Lehtinen | 1a01ebc | 2012-05-24 21:44:07 +0300 | [diff] [blame] | 627 | .. function:: fdopen(fd, *args, **kwargs) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 628 | |
Georg Brandl | b2462e2 | 2012-06-24 13:24:56 +0200 | [diff] [blame] | 629 | Return an open file object connected to the file descriptor *fd*. This is an |
| 630 | alias of the :func:`open` built-in function and accepts the same arguments. |
| 631 | The only difference is that the first argument of :func:`fdopen` must always |
| 632 | be an integer. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 633 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 634 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 635 | .. _os-fd-ops: |
| 636 | |
| 637 | File Descriptor Operations |
| 638 | -------------------------- |
| 639 | |
| 640 | These functions operate on I/O streams referenced using file descriptors. |
| 641 | |
| 642 | File descriptors are small integers corresponding to a file that has been opened |
| 643 | by the current process. For example, standard input is usually file descriptor |
| 644 | 0, standard output is 1, and standard error is 2. Further files opened by a |
| 645 | process will then be assigned 3, 4, 5, and so forth. The name "file descriptor" |
| 646 | is slightly deceptive; on Unix platforms, sockets and pipes are also referenced |
| 647 | by file descriptors. |
| 648 | |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 649 | The :meth:`~io.IOBase.fileno` method can be used to obtain the file descriptor |
Antoine Pitrou | 11cb961 | 2010-09-15 11:11:28 +0000 | [diff] [blame] | 650 | associated with a :term:`file object` when required. Note that using the file |
Benjamin Peterson | 08bf91c | 2010-04-11 16:12:57 +0000 | [diff] [blame] | 651 | descriptor directly will bypass the file object methods, ignoring aspects such |
| 652 | as internal buffering of data. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 653 | |
Antoine Pitrou | f65132d | 2011-02-25 23:25:17 +0000 | [diff] [blame] | 654 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 655 | .. function:: close(fd) |
| 656 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 657 | Close file descriptor *fd*. |
| 658 | |
| 659 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 660 | |
| 661 | .. note:: |
| 662 | |
| 663 | This function is intended for low-level I/O and must be applied to a file |
Benjamin Peterson | fa0d703 | 2009-06-01 22:42:33 +0000 | [diff] [blame] | 664 | descriptor as returned by :func:`os.open` or :func:`pipe`. To close a "file |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 665 | object" returned by the built-in function :func:`open` or by :func:`popen` or |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 666 | :func:`fdopen`, use its :meth:`~io.IOBase.close` method. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 667 | |
| 668 | |
Christian Heimes | fdab48e | 2008-01-20 09:06:41 +0000 | [diff] [blame] | 669 | .. function:: closerange(fd_low, fd_high) |
| 670 | |
| 671 | Close all file descriptors from *fd_low* (inclusive) to *fd_high* (exclusive), |
Georg Brandl | b1a1ac0 | 2012-06-24 11:54:07 +0200 | [diff] [blame] | 672 | ignoring errors. Equivalent to (but much faster than):: |
Christian Heimes | fdab48e | 2008-01-20 09:06:41 +0000 | [diff] [blame] | 673 | |
Georg Brandl | c9a5a0e | 2009-09-01 07:34:27 +0000 | [diff] [blame] | 674 | for fd in range(fd_low, fd_high): |
Christian Heimes | fdab48e | 2008-01-20 09:06:41 +0000 | [diff] [blame] | 675 | try: |
| 676 | os.close(fd) |
| 677 | except OSError: |
| 678 | pass |
| 679 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 680 | Availability: Unix, Windows. |
| 681 | |
Christian Heimes | fdab48e | 2008-01-20 09:06:41 +0000 | [diff] [blame] | 682 | |
Georg Brandl | 81f1130 | 2007-12-21 08:45:42 +0000 | [diff] [blame] | 683 | .. function:: device_encoding(fd) |
| 684 | |
| 685 | Return a string describing the encoding of the device associated with *fd* |
| 686 | if it is connected to a terminal; else return :const:`None`. |
| 687 | |
| 688 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 689 | .. function:: dup(fd) |
| 690 | |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 691 | Return a duplicate of file descriptor *fd*. The new file descriptor is |
| 692 | :ref:`non-inheritable <fd_inheritance>`. |
| 693 | |
| 694 | On Windows, when duplicating a standard stream (0: stdin, 1: stdout, |
| 695 | 2: stderr), the new file descriptor is :ref:`inheritable |
| 696 | <fd_inheritance>`. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 697 | |
| 698 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 699 | |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 700 | .. versionchanged:: 3.4 |
| 701 | The new file descriptor is now non-inheritable. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 702 | |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 703 | |
| 704 | .. function:: dup2(fd, fd2, inheritable=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 705 | |
| 706 | Duplicate file descriptor *fd* to *fd2*, closing the latter first if necessary. |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 707 | The file descriptor *fd2* is :ref:`inheritable <fd_inheritance>` by default, |
| 708 | or non-inheritable if *inheritable* is ``False``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 709 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 710 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 711 | |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 712 | .. versionchanged:: 3.4 |
| 713 | Add the optional *inheritable* parameter. |
| 714 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 715 | |
Christian Heimes | 4e30a84 | 2007-11-30 22:12:06 +0000 | [diff] [blame] | 716 | .. function:: fchmod(fd, mode) |
| 717 | |
Georg Brandl | b9df00c | 2012-06-24 12:38:14 +0200 | [diff] [blame] | 718 | Change the mode of the file given by *fd* to the numeric *mode*. See the |
Georg Brandl | 4d399a4 | 2012-06-25 07:40:32 +0200 | [diff] [blame] | 719 | docs for :func:`chmod` for possible values of *mode*. As of Python 3.3, this |
Georg Brandl | b9df00c | 2012-06-24 12:38:14 +0200 | [diff] [blame] | 720 | is equivalent to ``os.chmod(fd, mode)``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 721 | |
| 722 | Availability: Unix. |
Christian Heimes | 4e30a84 | 2007-11-30 22:12:06 +0000 | [diff] [blame] | 723 | |
| 724 | |
| 725 | .. function:: fchown(fd, uid, gid) |
| 726 | |
| 727 | Change the owner and group id of the file given by *fd* to the numeric *uid* |
Georg Brandl | b9df00c | 2012-06-24 12:38:14 +0200 | [diff] [blame] | 728 | and *gid*. To leave one of the ids unchanged, set it to -1. See |
Georg Brandl | 4d399a4 | 2012-06-25 07:40:32 +0200 | [diff] [blame] | 729 | :func:`chown`. As of Python 3.3, this is equivalent to ``os.chown(fd, uid, |
Georg Brandl | b9df00c | 2012-06-24 12:38:14 +0200 | [diff] [blame] | 730 | gid)``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 731 | |
Christian Heimes | 4e30a84 | 2007-11-30 22:12:06 +0000 | [diff] [blame] | 732 | Availability: Unix. |
| 733 | |
| 734 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 735 | .. function:: fdatasync(fd) |
| 736 | |
| 737 | Force write of file with filedescriptor *fd* to disk. Does not force update of |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 738 | metadata. |
| 739 | |
| 740 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 741 | |
Benjamin Peterson | fa0d703 | 2009-06-01 22:42:33 +0000 | [diff] [blame] | 742 | .. note:: |
| 743 | This function is not available on MacOS. |
| 744 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 745 | |
| 746 | .. function:: fpathconf(fd, name) |
| 747 | |
| 748 | Return system configuration information relevant to an open file. *name* |
| 749 | specifies the configuration value to retrieve; it may be a string which is the |
| 750 | name of a defined system value; these names are specified in a number of |
| 751 | standards (POSIX.1, Unix 95, Unix 98, and others). Some platforms define |
| 752 | additional names as well. The names known to the host operating system are |
| 753 | given in the ``pathconf_names`` dictionary. For configuration variables not |
| 754 | included in that mapping, passing an integer for *name* is also accepted. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 755 | |
| 756 | If *name* is a string and is not known, :exc:`ValueError` is raised. If a |
| 757 | specific value for *name* is not supported by the host system, even if it is |
| 758 | included in ``pathconf_names``, an :exc:`OSError` is raised with |
| 759 | :const:`errno.EINVAL` for the error number. |
| 760 | |
Georg Brandl | 4d399a4 | 2012-06-25 07:40:32 +0200 | [diff] [blame] | 761 | As of Python 3.3, this is equivalent to ``os.pathconf(fd, name)``. |
Georg Brandl | 306336b | 2012-06-24 12:55:33 +0200 | [diff] [blame] | 762 | |
Senthil Kumaran | 2a97cee | 2013-09-19 00:08:56 -0700 | [diff] [blame] | 763 | Availability: Unix. |
| 764 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 765 | |
Victor Stinner | 4195b5c | 2012-02-08 23:03:19 +0100 | [diff] [blame] | 766 | .. function:: fstat(fd) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 767 | |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 768 | Get the status of the file descriptor *fd*. Return a :class:`stat_result` |
| 769 | object. |
| 770 | |
| 771 | As of Python 3.3, this is equivalent to ``os.stat(fd)``. |
| 772 | |
| 773 | .. seealso:: |
| 774 | |
Berker Peksag | 2034caa | 2015-04-27 13:53:28 +0300 | [diff] [blame] | 775 | The :func:`.stat` function. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 776 | |
| 777 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 778 | |
Georg Brandl | b1a1ac0 | 2012-06-24 11:54:07 +0200 | [diff] [blame] | 779 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 780 | .. function:: fstatvfs(fd) |
| 781 | |
Georg Brandl | b9df00c | 2012-06-24 12:38:14 +0200 | [diff] [blame] | 782 | Return information about the filesystem containing the file associated with |
Georg Brandl | 4d399a4 | 2012-06-25 07:40:32 +0200 | [diff] [blame] | 783 | file descriptor *fd*, like :func:`statvfs`. As of Python 3.3, this is |
Georg Brandl | b9df00c | 2012-06-24 12:38:14 +0200 | [diff] [blame] | 784 | equivalent to ``os.statvfs(fd)``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 785 | |
| 786 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 787 | |
| 788 | |
| 789 | .. function:: fsync(fd) |
| 790 | |
| 791 | Force write of file with filedescriptor *fd* to disk. On Unix, this calls the |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 792 | native :c:func:`fsync` function; on Windows, the MS :c:func:`_commit` function. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 793 | |
Antoine Pitrou | 11cb961 | 2010-09-15 11:11:28 +0000 | [diff] [blame] | 794 | If you're starting with a buffered Python :term:`file object` *f*, first do |
| 795 | ``f.flush()``, and then do ``os.fsync(f.fileno())``, to ensure that all internal |
| 796 | buffers associated with *f* are written to disk. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 797 | |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 798 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 799 | |
| 800 | |
| 801 | .. function:: ftruncate(fd, length) |
| 802 | |
Georg Brandl | 306336b | 2012-06-24 12:55:33 +0200 | [diff] [blame] | 803 | Truncate the file corresponding to file descriptor *fd*, so that it is at |
Georg Brandl | 4d399a4 | 2012-06-25 07:40:32 +0200 | [diff] [blame] | 804 | most *length* bytes in size. As of Python 3.3, this is equivalent to |
Georg Brandl | 306336b | 2012-06-24 12:55:33 +0200 | [diff] [blame] | 805 | ``os.truncate(fd, length)``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 806 | |
| 807 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 808 | |
| 809 | |
| 810 | .. function:: isatty(fd) |
| 811 | |
| 812 | Return ``True`` if the file descriptor *fd* is open and connected to a |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 813 | tty(-like) device, else ``False``. |
| 814 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 815 | |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 816 | .. function:: lockf(fd, cmd, len) |
| 817 | |
| 818 | Apply, test or remove a POSIX lock on an open file descriptor. |
| 819 | *fd* is an open file descriptor. |
| 820 | *cmd* specifies the command to use - one of :data:`F_LOCK`, :data:`F_TLOCK`, |
| 821 | :data:`F_ULOCK` or :data:`F_TEST`. |
| 822 | *len* specifies the section of the file to lock. |
| 823 | |
| 824 | Availability: Unix. |
| 825 | |
| 826 | .. versionadded:: 3.3 |
| 827 | |
| 828 | |
| 829 | .. data:: F_LOCK |
| 830 | F_TLOCK |
| 831 | F_ULOCK |
| 832 | F_TEST |
| 833 | |
| 834 | Flags that specify what action :func:`lockf` will take. |
| 835 | |
| 836 | Availability: Unix. |
| 837 | |
| 838 | .. versionadded:: 3.3 |
| 839 | |
Georg Brandl | f62445a | 2012-06-24 13:31:20 +0200 | [diff] [blame] | 840 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 841 | .. function:: lseek(fd, pos, how) |
| 842 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 843 | Set the current position of file descriptor *fd* to position *pos*, modified |
| 844 | by *how*: :const:`SEEK_SET` or ``0`` to set the position relative to the |
| 845 | beginning of the file; :const:`SEEK_CUR` or ``1`` to set it relative to the |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 846 | current position; :const:`SEEK_END` or ``2`` to set it relative to the end of |
Victor Stinner | e83f899 | 2011-12-17 23:15:09 +0100 | [diff] [blame] | 847 | the file. Return the new cursor position in bytes, starting from the beginning. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 848 | |
| 849 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 850 | |
| 851 | |
Georg Brandl | 8569e58 | 2010-05-19 20:57:08 +0000 | [diff] [blame] | 852 | .. data:: SEEK_SET |
| 853 | SEEK_CUR |
| 854 | SEEK_END |
| 855 | |
| 856 | Parameters to the :func:`lseek` function. Their values are 0, 1, and 2, |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 857 | respectively. |
| 858 | |
| 859 | Availability: Unix, Windows. |
Georg Brandl | 8569e58 | 2010-05-19 20:57:08 +0000 | [diff] [blame] | 860 | |
Jesus Cea | 9436361 | 2012-06-22 18:32:07 +0200 | [diff] [blame] | 861 | .. versionadded:: 3.3 |
| 862 | Some operating systems could support additional values, like |
| 863 | :data:`os.SEEK_HOLE` or :data:`os.SEEK_DATA`. |
| 864 | |
Georg Brandl | 8569e58 | 2010-05-19 20:57:08 +0000 | [diff] [blame] | 865 | |
Martin Panter | bf19d16 | 2015-09-09 01:01:13 +0000 | [diff] [blame] | 866 | .. function:: open(path, flags, mode=0o777, *, dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 867 | |
Martin Panter | bf19d16 | 2015-09-09 01:01:13 +0000 | [diff] [blame] | 868 | Open the file *path* and set various flags according to *flags* and possibly |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 869 | its mode according to *mode*. When computing *mode*, the current umask value |
| 870 | is first masked out. Return the file descriptor for the newly opened file. |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 871 | The new file descriptor is :ref:`non-inheritable <fd_inheritance>`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 872 | |
| 873 | For a description of the flag and mode values, see the C run-time documentation; |
| 874 | flag constants (like :const:`O_RDONLY` and :const:`O_WRONLY`) are defined in |
Andrew Kuchling | 4921a08 | 2013-06-21 11:49:57 -0400 | [diff] [blame] | 875 | the :mod:`os` module. In particular, on Windows adding |
Georg Brandl | 8569e58 | 2010-05-19 20:57:08 +0000 | [diff] [blame] | 876 | :const:`O_BINARY` is needed to open files in binary mode. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 877 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 878 | This function can support :ref:`paths relative to directory descriptors |
Andrew Kuchling | 4921a08 | 2013-06-21 11:49:57 -0400 | [diff] [blame] | 879 | <dir_fd>` with the *dir_fd* parameter. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 880 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 881 | Availability: Unix, Windows. |
| 882 | |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 883 | .. versionchanged:: 3.4 |
| 884 | The new file descriptor is now non-inheritable. |
| 885 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 886 | .. note:: |
| 887 | |
Georg Brandl | 502d9a5 | 2009-07-26 15:02:41 +0000 | [diff] [blame] | 888 | This function is intended for low-level I/O. For normal usage, use the |
Antoine Pitrou | 11cb961 | 2010-09-15 11:11:28 +0000 | [diff] [blame] | 889 | built-in function :func:`open`, which returns a :term:`file object` with |
Jeroen Ruigrok van der Werven | 9c558bcf | 2010-07-13 14:47:01 +0000 | [diff] [blame] | 890 | :meth:`~file.read` and :meth:`~file.write` methods (and many more). To |
Antoine Pitrou | 11cb961 | 2010-09-15 11:11:28 +0000 | [diff] [blame] | 891 | wrap a file descriptor in a file object, use :func:`fdopen`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 892 | |
Antoine Pitrou | f65132d | 2011-02-25 23:25:17 +0000 | [diff] [blame] | 893 | .. versionadded:: 3.3 |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 894 | The *dir_fd* argument. |
Antoine Pitrou | f65132d | 2011-02-25 23:25:17 +0000 | [diff] [blame] | 895 | |
Andrew Kuchling | 4921a08 | 2013-06-21 11:49:57 -0400 | [diff] [blame] | 896 | The following constants are options for the *flags* parameter to the |
| 897 | :func:`~os.open` function. They can be combined using the bitwise OR operator |
| 898 | ``|``. Some of them are not available on all platforms. For descriptions of |
| 899 | their availability and use, consult the :manpage:`open(2)` manual page on Unix |
| 900 | or `the MSDN <http://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Windows. |
| 901 | |
| 902 | |
| 903 | .. data:: O_RDONLY |
| 904 | O_WRONLY |
| 905 | O_RDWR |
| 906 | O_APPEND |
| 907 | O_CREAT |
| 908 | O_EXCL |
| 909 | O_TRUNC |
| 910 | |
| 911 | These constants are available on Unix and Windows. |
| 912 | |
| 913 | |
| 914 | .. data:: O_DSYNC |
| 915 | O_RSYNC |
| 916 | O_SYNC |
| 917 | O_NDELAY |
| 918 | O_NONBLOCK |
| 919 | O_NOCTTY |
| 920 | O_SHLOCK |
| 921 | O_EXLOCK |
| 922 | O_CLOEXEC |
| 923 | |
| 924 | These constants are only available on Unix. |
| 925 | |
| 926 | .. versionchanged:: 3.3 |
| 927 | Add :data:`O_CLOEXEC` constant. |
| 928 | |
| 929 | .. data:: O_BINARY |
| 930 | O_NOINHERIT |
| 931 | O_SHORT_LIVED |
| 932 | O_TEMPORARY |
| 933 | O_RANDOM |
| 934 | O_SEQUENTIAL |
| 935 | O_TEXT |
| 936 | |
| 937 | These constants are only available on Windows. |
| 938 | |
| 939 | |
| 940 | .. data:: O_ASYNC |
| 941 | O_DIRECT |
| 942 | O_DIRECTORY |
| 943 | O_NOFOLLOW |
| 944 | O_NOATIME |
| 945 | O_PATH |
Christian Heimes | 177b3f9 | 2013-08-16 14:35:09 +0200 | [diff] [blame] | 946 | O_TMPFILE |
Andrew Kuchling | 4921a08 | 2013-06-21 11:49:57 -0400 | [diff] [blame] | 947 | |
| 948 | These constants are GNU extensions and not present if they are not defined by |
| 949 | the C library. |
| 950 | |
Christian Heimes | d88f735 | 2013-08-16 14:37:50 +0200 | [diff] [blame] | 951 | .. versionchanged:: 3.4 |
Larry Hastings | 3732ed2 | 2014-03-15 21:13:56 -0700 | [diff] [blame] | 952 | Add :data:`O_PATH` on systems that support it. |
| 953 | Add :data:`O_TMPFILE`, only available on Linux Kernel 3.11 |
| 954 | or newer. |
Christian Heimes | d88f735 | 2013-08-16 14:37:50 +0200 | [diff] [blame] | 955 | |
Antoine Pitrou | f65132d | 2011-02-25 23:25:17 +0000 | [diff] [blame] | 956 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 957 | .. function:: openpty() |
| 958 | |
| 959 | .. index:: module: pty |
| 960 | |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 961 | Open a new pseudo-terminal pair. Return a pair of file descriptors |
| 962 | ``(master, slave)`` for the pty and the tty, respectively. The new file |
| 963 | descriptors are :ref:`non-inheritable <fd_inheritance>`. For a (slightly) more |
| 964 | portable approach, use the :mod:`pty` module. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 965 | |
| 966 | Availability: some flavors of Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 967 | |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 968 | .. versionchanged:: 3.4 |
| 969 | The new file descriptors are now non-inheritable. |
| 970 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 971 | |
| 972 | .. function:: pipe() |
| 973 | |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 974 | Create a pipe. Return a pair of file descriptors ``(r, w)`` usable for |
Victor Stinner | 05f31bf | 2013-11-06 01:48:45 +0100 | [diff] [blame] | 975 | reading and writing, respectively. The new file descriptor is |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 976 | :ref:`non-inheritable <fd_inheritance>`. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 977 | |
| 978 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 979 | |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 980 | .. versionchanged:: 3.4 |
| 981 | The new file descriptors are now non-inheritable. |
| 982 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 983 | |
Charles-François Natali | 368f34b | 2011-06-06 19:49:47 +0200 | [diff] [blame] | 984 | .. function:: pipe2(flags) |
Charles-François Natali | daafdd5 | 2011-05-29 20:07:40 +0200 | [diff] [blame] | 985 | |
| 986 | Create a pipe with *flags* set atomically. |
Charles-François Natali | 368f34b | 2011-06-06 19:49:47 +0200 | [diff] [blame] | 987 | *flags* can be constructed by ORing together one or more of these values: |
| 988 | :data:`O_NONBLOCK`, :data:`O_CLOEXEC`. |
Charles-François Natali | daafdd5 | 2011-05-29 20:07:40 +0200 | [diff] [blame] | 989 | Return a pair of file descriptors ``(r, w)`` usable for reading and writing, |
| 990 | respectively. |
| 991 | |
| 992 | Availability: some flavors of Unix. |
| 993 | |
| 994 | .. versionadded:: 3.3 |
| 995 | |
| 996 | |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 997 | .. function:: posix_fallocate(fd, offset, len) |
| 998 | |
| 999 | Ensures that enough disk space is allocated for the file specified by *fd* |
| 1000 | starting from *offset* and continuing for *len* bytes. |
| 1001 | |
| 1002 | Availability: Unix. |
| 1003 | |
| 1004 | .. versionadded:: 3.3 |
| 1005 | |
| 1006 | |
| 1007 | .. function:: posix_fadvise(fd, offset, len, advice) |
| 1008 | |
| 1009 | Announces an intention to access data in a specific pattern thus allowing |
| 1010 | the kernel to make optimizations. |
| 1011 | The advice applies to the region of the file specified by *fd* starting at |
| 1012 | *offset* and continuing for *len* bytes. |
| 1013 | *advice* is one of :data:`POSIX_FADV_NORMAL`, :data:`POSIX_FADV_SEQUENTIAL`, |
| 1014 | :data:`POSIX_FADV_RANDOM`, :data:`POSIX_FADV_NOREUSE`, |
| 1015 | :data:`POSIX_FADV_WILLNEED` or :data:`POSIX_FADV_DONTNEED`. |
| 1016 | |
| 1017 | Availability: Unix. |
| 1018 | |
| 1019 | .. versionadded:: 3.3 |
| 1020 | |
| 1021 | |
| 1022 | .. data:: POSIX_FADV_NORMAL |
| 1023 | POSIX_FADV_SEQUENTIAL |
| 1024 | POSIX_FADV_RANDOM |
| 1025 | POSIX_FADV_NOREUSE |
| 1026 | POSIX_FADV_WILLNEED |
| 1027 | POSIX_FADV_DONTNEED |
| 1028 | |
| 1029 | Flags that can be used in *advice* in :func:`posix_fadvise` that specify |
| 1030 | the access pattern that is likely to be used. |
| 1031 | |
| 1032 | Availability: Unix. |
| 1033 | |
| 1034 | .. versionadded:: 3.3 |
| 1035 | |
| 1036 | |
| 1037 | .. function:: pread(fd, buffersize, offset) |
| 1038 | |
| 1039 | Read from a file descriptor, *fd*, at a position of *offset*. It will read up |
| 1040 | to *buffersize* number of bytes. The file offset remains unchanged. |
| 1041 | |
| 1042 | Availability: Unix. |
| 1043 | |
| 1044 | .. versionadded:: 3.3 |
| 1045 | |
| 1046 | |
Jesus Cea | 67503c5 | 2014-10-20 16:18:24 +0200 | [diff] [blame] | 1047 | .. function:: pwrite(fd, str, offset) |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 1048 | |
Jesus Cea | 67503c5 | 2014-10-20 16:18:24 +0200 | [diff] [blame] | 1049 | Write *bytestring* to a file descriptor, *fd*, from *offset*, |
| 1050 | leaving the file offset unchanged. |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 1051 | |
| 1052 | Availability: Unix. |
| 1053 | |
| 1054 | .. versionadded:: 3.3 |
| 1055 | |
| 1056 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1057 | .. function:: read(fd, n) |
| 1058 | |
Georg Brandl | b90be69 | 2009-07-29 16:14:16 +0000 | [diff] [blame] | 1059 | Read at most *n* bytes from file descriptor *fd*. Return a bytestring containing the |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1060 | bytes read. If the end of the file referred to by *fd* has been reached, an |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1061 | empty bytes object is returned. |
| 1062 | |
| 1063 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1064 | |
| 1065 | .. note:: |
| 1066 | |
| 1067 | This function is intended for low-level I/O and must be applied to a file |
Georg Brandl | b2462e2 | 2012-06-24 13:24:56 +0200 | [diff] [blame] | 1068 | descriptor as returned by :func:`os.open` or :func:`pipe`. To read a |
| 1069 | "file object" returned by the built-in function :func:`open` or by |
| 1070 | :func:`popen` or :func:`fdopen`, or :data:`sys.stdin`, use its |
| 1071 | :meth:`~file.read` or :meth:`~file.readline` methods. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1072 | |
| 1073 | |
Martin Panter | bf19d16 | 2015-09-09 01:01:13 +0000 | [diff] [blame] | 1074 | .. function:: sendfile(out, in, offset, count) |
Martin Panter | 9499413 | 2015-09-09 05:29:24 +0000 | [diff] [blame] | 1075 | sendfile(out, in, offset, count, [headers], [trailers], flags=0) |
Giampaolo Rodolà | c9c2c8b | 2011-02-25 14:39:16 +0000 | [diff] [blame] | 1076 | |
Martin Panter | bf19d16 | 2015-09-09 01:01:13 +0000 | [diff] [blame] | 1077 | Copy *count* bytes from file descriptor *in* to file descriptor *out* |
Giampaolo Rodolà | c9c2c8b | 2011-02-25 14:39:16 +0000 | [diff] [blame] | 1078 | starting at *offset*. |
| 1079 | Return the number of bytes sent. When EOF is reached return 0. |
| 1080 | |
| 1081 | The first function notation is supported by all platforms that define |
| 1082 | :func:`sendfile`. |
| 1083 | |
| 1084 | On Linux, if *offset* is given as ``None``, the bytes are read from the |
| 1085 | current position of *in* and the position of *in* is updated. |
| 1086 | |
| 1087 | The second case may be used on Mac OS X and FreeBSD where *headers* and |
| 1088 | *trailers* are arbitrary sequences of buffers that are written before and |
| 1089 | after the data from *in* is written. It returns the same as the first case. |
| 1090 | |
Martin Panter | bf19d16 | 2015-09-09 01:01:13 +0000 | [diff] [blame] | 1091 | On Mac OS X and FreeBSD, a value of 0 for *count* specifies to send until |
Giampaolo Rodolà | c9c2c8b | 2011-02-25 14:39:16 +0000 | [diff] [blame] | 1092 | the end of *in* is reached. |
| 1093 | |
Charles-Francois Natali | a771a1b | 2013-05-01 15:12:20 +0200 | [diff] [blame] | 1094 | All platforms support sockets as *out* file descriptor, and some platforms |
| 1095 | allow other types (e.g. regular file, pipe) as well. |
Giampaolo Rodolà | c9c2c8b | 2011-02-25 14:39:16 +0000 | [diff] [blame] | 1096 | |
Victor Stinner | 992019c | 2014-07-24 12:42:45 +0200 | [diff] [blame] | 1097 | Cross-platform applications should not use *headers*, *trailers* and *flags* |
| 1098 | arguments. |
| 1099 | |
Giampaolo Rodolà | c9c2c8b | 2011-02-25 14:39:16 +0000 | [diff] [blame] | 1100 | Availability: Unix. |
| 1101 | |
| 1102 | .. versionadded:: 3.3 |
| 1103 | |
| 1104 | |
| 1105 | .. data:: SF_NODISKIO |
| 1106 | SF_MNOWAIT |
| 1107 | SF_SYNC |
| 1108 | |
| 1109 | Parameters to the :func:`sendfile` function, if the implementation supports |
| 1110 | them. |
| 1111 | |
| 1112 | Availability: Unix. |
| 1113 | |
| 1114 | .. versionadded:: 3.3 |
| 1115 | |
| 1116 | |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 1117 | .. function:: readv(fd, buffers) |
| 1118 | |
Benjamin Peterson | e83ed43 | 2014-01-18 22:54:59 -0500 | [diff] [blame] | 1119 | Read from a file descriptor *fd* into a number of mutable :term:`bytes-like |
| 1120 | objects <bytes-like object>` *buffers*. :func:`~os.readv` will transfer data |
| 1121 | into each buffer until it is full and then move on to the next buffer in the |
| 1122 | sequence to hold the rest of the data. :func:`~os.readv` returns the total |
| 1123 | number of bytes read (which may be less than the total capacity of all the |
| 1124 | objects). |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 1125 | |
| 1126 | Availability: Unix. |
| 1127 | |
| 1128 | .. versionadded:: 3.3 |
| 1129 | |
| 1130 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1131 | .. function:: tcgetpgrp(fd) |
| 1132 | |
| 1133 | Return the process group associated with the terminal given by *fd* (an open |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1134 | file descriptor as returned by :func:`os.open`). |
| 1135 | |
| 1136 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1137 | |
| 1138 | |
| 1139 | .. function:: tcsetpgrp(fd, pg) |
| 1140 | |
| 1141 | Set the process group associated with the terminal given by *fd* (an open file |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1142 | descriptor as returned by :func:`os.open`) to *pg*. |
| 1143 | |
| 1144 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1145 | |
| 1146 | |
| 1147 | .. function:: ttyname(fd) |
| 1148 | |
| 1149 | Return a string which specifies the terminal device associated with |
Georg Brandl | 9afde1c | 2007-11-01 20:32:30 +0000 | [diff] [blame] | 1150 | file descriptor *fd*. If *fd* is not associated with a terminal device, an |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1151 | exception is raised. |
| 1152 | |
| 1153 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1154 | |
| 1155 | |
| 1156 | .. function:: write(fd, str) |
| 1157 | |
Georg Brandl | b90be69 | 2009-07-29 16:14:16 +0000 | [diff] [blame] | 1158 | Write the bytestring in *str* to file descriptor *fd*. Return the number of |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1159 | bytes actually written. |
| 1160 | |
| 1161 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1162 | |
| 1163 | .. note:: |
| 1164 | |
| 1165 | This function is intended for low-level I/O and must be applied to a file |
Benjamin Peterson | fa0d703 | 2009-06-01 22:42:33 +0000 | [diff] [blame] | 1166 | descriptor as returned by :func:`os.open` or :func:`pipe`. To write a "file |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1167 | object" returned by the built-in function :func:`open` or by :func:`popen` or |
Benjamin Peterson | fa0d703 | 2009-06-01 22:42:33 +0000 | [diff] [blame] | 1168 | :func:`fdopen`, or :data:`sys.stdout` or :data:`sys.stderr`, use its |
| 1169 | :meth:`~file.write` method. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1170 | |
Georg Brandl | 8569e58 | 2010-05-19 20:57:08 +0000 | [diff] [blame] | 1171 | |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 1172 | .. function:: writev(fd, buffers) |
| 1173 | |
Benjamin Peterson | e83ed43 | 2014-01-18 22:54:59 -0500 | [diff] [blame] | 1174 | Write the contents of *buffers* to file descriptor *fd*. *buffers* must be a |
| 1175 | sequence of :term:`bytes-like objects <bytes-like object>`. |
| 1176 | :func:`~os.writev` writes the contents of each object to the file descriptor |
| 1177 | and returns the total number of bytes written. |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 1178 | |
| 1179 | Availability: Unix. |
| 1180 | |
| 1181 | .. versionadded:: 3.3 |
| 1182 | |
| 1183 | |
Antoine Pitrou | bcf2b59 | 2012-02-08 23:28:36 +0100 | [diff] [blame] | 1184 | .. _terminal-size: |
| 1185 | |
| 1186 | Querying the size of a terminal |
| 1187 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 1188 | |
| 1189 | .. versionadded:: 3.3 |
| 1190 | |
| 1191 | .. function:: get_terminal_size(fd=STDOUT_FILENO) |
| 1192 | |
| 1193 | Return the size of the terminal window as ``(columns, lines)``, |
| 1194 | tuple of type :class:`terminal_size`. |
| 1195 | |
| 1196 | The optional argument ``fd`` (default ``STDOUT_FILENO``, or standard |
| 1197 | output) specifies which file descriptor should be queried. |
| 1198 | |
| 1199 | If the file descriptor is not connected to a terminal, an :exc:`OSError` |
Andrew Svetlov | 5b89840 | 2012-12-18 21:26:36 +0200 | [diff] [blame] | 1200 | is raised. |
Antoine Pitrou | bcf2b59 | 2012-02-08 23:28:36 +0100 | [diff] [blame] | 1201 | |
| 1202 | :func:`shutil.get_terminal_size` is the high-level function which |
| 1203 | should normally be used, ``os.get_terminal_size`` is the low-level |
| 1204 | implementation. |
| 1205 | |
| 1206 | Availability: Unix, Windows. |
| 1207 | |
Georg Brandl | 6cff9ff | 2012-06-24 14:05:40 +0200 | [diff] [blame] | 1208 | .. class:: terminal_size |
Antoine Pitrou | bcf2b59 | 2012-02-08 23:28:36 +0100 | [diff] [blame] | 1209 | |
Georg Brandl | 6cff9ff | 2012-06-24 14:05:40 +0200 | [diff] [blame] | 1210 | A subclass of tuple, holding ``(columns, lines)`` of the terminal window size. |
Antoine Pitrou | bcf2b59 | 2012-02-08 23:28:36 +0100 | [diff] [blame] | 1211 | |
| 1212 | .. attribute:: columns |
| 1213 | |
| 1214 | Width of the terminal window in characters. |
| 1215 | |
| 1216 | .. attribute:: lines |
| 1217 | |
| 1218 | Height of the terminal window in characters. |
| 1219 | |
| 1220 | |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 1221 | .. _fd_inheritance: |
| 1222 | |
| 1223 | Inheritance of File Descriptors |
| 1224 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 1225 | |
Georg Brandl | 5642ff9 | 2013-09-15 10:37:57 +0200 | [diff] [blame] | 1226 | .. versionadded:: 3.4 |
| 1227 | |
| 1228 | A file descriptor has an "inheritable" flag which indicates if the file descriptor |
| 1229 | can be inherited by child processes. Since Python 3.4, file descriptors |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 1230 | created by Python are non-inheritable by default. |
| 1231 | |
| 1232 | On UNIX, non-inheritable file descriptors are closed in child processes at the |
| 1233 | execution of a new program, other file descriptors are inherited. |
| 1234 | |
| 1235 | On Windows, non-inheritable handles and file descriptors are closed in child |
Georg Brandl | 5642ff9 | 2013-09-15 10:37:57 +0200 | [diff] [blame] | 1236 | processes, except for standard streams (file descriptors 0, 1 and 2: stdin, stdout |
Serhiy Storchaka | 690a6a9 | 2013-10-13 20:13:37 +0300 | [diff] [blame] | 1237 | and stderr), which are always inherited. Using :func:`spawn\* <spawnl>` functions, |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 1238 | all inheritable handles and all inheritable file descriptors are inherited. |
| 1239 | Using the :mod:`subprocess` module, all file descriptors except standard |
Georg Brandl | 5642ff9 | 2013-09-15 10:37:57 +0200 | [diff] [blame] | 1240 | streams are closed, and inheritable handles are only inherited if the |
| 1241 | *close_fds* parameter is ``False``. |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 1242 | |
| 1243 | .. function:: get_inheritable(fd) |
| 1244 | |
Georg Brandl | 5642ff9 | 2013-09-15 10:37:57 +0200 | [diff] [blame] | 1245 | Get the "inheritable" flag of the specified file descriptor (a boolean). |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 1246 | |
| 1247 | .. function:: set_inheritable(fd, inheritable) |
| 1248 | |
Georg Brandl | 5642ff9 | 2013-09-15 10:37:57 +0200 | [diff] [blame] | 1249 | Set the "inheritable" flag of the specified file descriptor. |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 1250 | |
| 1251 | .. function:: get_handle_inheritable(handle) |
| 1252 | |
Georg Brandl | 5642ff9 | 2013-09-15 10:37:57 +0200 | [diff] [blame] | 1253 | Get the "inheritable" flag of the specified handle (a boolean). |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 1254 | |
| 1255 | Availability: Windows. |
| 1256 | |
| 1257 | .. function:: set_handle_inheritable(handle, inheritable) |
| 1258 | |
Georg Brandl | 5642ff9 | 2013-09-15 10:37:57 +0200 | [diff] [blame] | 1259 | Set the "inheritable" flag of the specified handle. |
Victor Stinner | daf4555 | 2013-08-28 00:53:59 +0200 | [diff] [blame] | 1260 | |
| 1261 | Availability: Windows. |
| 1262 | |
| 1263 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1264 | .. _os-file-dir: |
| 1265 | |
| 1266 | Files and Directories |
| 1267 | --------------------- |
| 1268 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1269 | On some Unix platforms, many of these functions support one or more of these |
| 1270 | features: |
| 1271 | |
| 1272 | .. _path_fd: |
| 1273 | |
Larry Hastings | 77892dc | 2012-06-25 03:27:33 -0700 | [diff] [blame] | 1274 | * **specifying a file descriptor:** |
| 1275 | For some functions, the *path* argument can be not only a string giving a path |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1276 | name, but also a file descriptor. The function will then operate on the file |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 1277 | referred to by the descriptor. (For POSIX systems, Python will call the |
| 1278 | ``f...`` version of the function.) |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1279 | |
| 1280 | You can check whether or not *path* can be specified as a file descriptor on |
| 1281 | your platform using :data:`os.supports_fd`. If it is unavailable, using it |
| 1282 | will raise a :exc:`NotImplementedError`. |
| 1283 | |
| 1284 | If the function also supports *dir_fd* or *follow_symlinks* arguments, it is |
| 1285 | an error to specify one of those when supplying *path* as a file descriptor. |
| 1286 | |
| 1287 | .. _dir_fd: |
| 1288 | |
Larry Hastings | 77892dc | 2012-06-25 03:27:33 -0700 | [diff] [blame] | 1289 | * **paths relative to directory descriptors:** If *dir_fd* is not ``None``, it |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1290 | should be a file descriptor referring to a directory, and the path to operate |
| 1291 | on should be relative; path will then be relative to that directory. If the |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 1292 | path is absolute, *dir_fd* is ignored. (For POSIX systems, Python will call |
Larry Hastings | 77892dc | 2012-06-25 03:27:33 -0700 | [diff] [blame] | 1293 | the ``...at`` or ``f...at`` version of the function.) |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1294 | |
| 1295 | You can check whether or not *dir_fd* is supported on your platform using |
| 1296 | :data:`os.supports_dir_fd`. If it is unavailable, using it will raise a |
| 1297 | :exc:`NotImplementedError`. |
| 1298 | |
| 1299 | .. _follow_symlinks: |
| 1300 | |
Larry Hastings | 77892dc | 2012-06-25 03:27:33 -0700 | [diff] [blame] | 1301 | * **not following symlinks:** If *follow_symlinks* is |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1302 | ``False``, and the last element of the path to operate on is a symbolic link, |
| 1303 | the function will operate on the symbolic link itself instead of the file the |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 1304 | link points to. (For POSIX systems, Python will call the ``l...`` version of |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1305 | the function.) |
| 1306 | |
| 1307 | You can check whether or not *follow_symlinks* is supported on your platform |
| 1308 | using :data:`os.supports_follow_symlinks`. If it is unavailable, using it |
| 1309 | will raise a :exc:`NotImplementedError`. |
| 1310 | |
| 1311 | |
| 1312 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1313 | .. function:: access(path, mode, *, dir_fd=None, effective_ids=False, follow_symlinks=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1314 | |
| 1315 | Use the real uid/gid to test for access to *path*. Note that most operations |
| 1316 | will use the effective uid/gid, therefore this routine can be used in a |
| 1317 | suid/sgid environment to test if the invoking user has the specified access to |
| 1318 | *path*. *mode* should be :const:`F_OK` to test the existence of *path*, or it |
| 1319 | can be the inclusive OR of one or more of :const:`R_OK`, :const:`W_OK`, and |
| 1320 | :const:`X_OK` to test permissions. Return :const:`True` if access is allowed, |
| 1321 | :const:`False` if not. See the Unix man page :manpage:`access(2)` for more |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1322 | information. |
| 1323 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1324 | This function can support specifying :ref:`paths relative to directory |
| 1325 | descriptors <dir_fd>` and :ref:`not following symlinks <follow_symlinks>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1326 | |
| 1327 | If *effective_ids* is ``True``, :func:`access` will perform its access |
| 1328 | checks using the effective uid/gid instead of the real uid/gid. |
| 1329 | *effective_ids* may not be supported on your platform; you can check whether |
| 1330 | or not it is available using :data:`os.supports_effective_ids`. If it is |
| 1331 | unavailable, using it will raise a :exc:`NotImplementedError`. |
| 1332 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1333 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1334 | |
| 1335 | .. note:: |
| 1336 | |
Georg Brandl | 502d9a5 | 2009-07-26 15:02:41 +0000 | [diff] [blame] | 1337 | Using :func:`access` to check if a user is authorized to e.g. open a file |
| 1338 | before actually doing so using :func:`open` creates a security hole, |
| 1339 | because the user might exploit the short time interval between checking |
Benjamin Peterson | 249b508 | 2011-05-20 11:41:13 -0500 | [diff] [blame] | 1340 | and opening the file to manipulate it. It's preferable to use :term:`EAFP` |
| 1341 | techniques. For example:: |
| 1342 | |
| 1343 | if os.access("myfile", os.R_OK): |
| 1344 | with open("myfile") as fp: |
| 1345 | return fp.read() |
| 1346 | return "some default data" |
| 1347 | |
| 1348 | is better written as:: |
| 1349 | |
| 1350 | try: |
| 1351 | fp = open("myfile") |
Antoine Pitrou | 62ab10a0 | 2011-10-12 20:10:51 +0200 | [diff] [blame] | 1352 | except PermissionError: |
| 1353 | return "some default data" |
Benjamin Peterson | 249b508 | 2011-05-20 11:41:13 -0500 | [diff] [blame] | 1354 | else: |
| 1355 | with fp: |
| 1356 | return fp.read() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1357 | |
| 1358 | .. note:: |
| 1359 | |
| 1360 | I/O operations may fail even when :func:`access` indicates that they would |
| 1361 | succeed, particularly for operations on network filesystems which may have |
| 1362 | permissions semantics beyond the usual POSIX permission-bit model. |
| 1363 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1364 | .. versionchanged:: 3.3 |
| 1365 | Added the *dir_fd*, *effective_ids*, and *follow_symlinks* parameters. |
| 1366 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1367 | |
| 1368 | .. data:: F_OK |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1369 | R_OK |
| 1370 | W_OK |
| 1371 | X_OK |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1372 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1373 | Values to pass as the *mode* parameter of :func:`access` to test the |
| 1374 | existence, readability, writability and executability of *path*, |
| 1375 | respectively. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1376 | |
| 1377 | |
| 1378 | .. function:: chdir(path) |
| 1379 | |
| 1380 | .. index:: single: directory; changing |
| 1381 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1382 | Change the current working directory to *path*. |
| 1383 | |
Larry Hastings | 77892dc | 2012-06-25 03:27:33 -0700 | [diff] [blame] | 1384 | This function can support :ref:`specifying a file descriptor <path_fd>`. The |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1385 | descriptor must refer to an opened directory, not an open file. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1386 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1387 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1388 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1389 | .. versionadded:: 3.3 |
| 1390 | Added support for specifying *path* as a file descriptor |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1391 | on some platforms. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1392 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1393 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1394 | .. function:: chflags(path, flags, *, follow_symlinks=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1395 | |
| 1396 | Set the flags of *path* to the numeric *flags*. *flags* may take a combination |
| 1397 | (bitwise OR) of the following values (as defined in the :mod:`stat` module): |
| 1398 | |
R David Murray | 3017806 | 2011-03-10 17:18:33 -0500 | [diff] [blame] | 1399 | * :data:`stat.UF_NODUMP` |
| 1400 | * :data:`stat.UF_IMMUTABLE` |
| 1401 | * :data:`stat.UF_APPEND` |
| 1402 | * :data:`stat.UF_OPAQUE` |
| 1403 | * :data:`stat.UF_NOUNLINK` |
Ned Deily | 3eb67d5 | 2011-06-28 00:00:28 -0700 | [diff] [blame] | 1404 | * :data:`stat.UF_COMPRESSED` |
| 1405 | * :data:`stat.UF_HIDDEN` |
R David Murray | 3017806 | 2011-03-10 17:18:33 -0500 | [diff] [blame] | 1406 | * :data:`stat.SF_ARCHIVED` |
| 1407 | * :data:`stat.SF_IMMUTABLE` |
| 1408 | * :data:`stat.SF_APPEND` |
| 1409 | * :data:`stat.SF_NOUNLINK` |
| 1410 | * :data:`stat.SF_SNAPSHOT` |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1411 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1412 | This function can support :ref:`not following symlinks <follow_symlinks>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1413 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 1414 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1415 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1416 | .. versionadded:: 3.3 |
| 1417 | The *follow_symlinks* argument. |
| 1418 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1419 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1420 | .. function:: chmod(path, mode, *, dir_fd=None, follow_symlinks=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1421 | |
| 1422 | Change the mode of *path* to the numeric *mode*. *mode* may take one of the |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 1423 | following values (as defined in the :mod:`stat` module) or bitwise ORed |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1424 | combinations of them: |
| 1425 | |
Alexandre Vassalotti | c22c6f2 | 2009-07-21 00:51:58 +0000 | [diff] [blame] | 1426 | * :data:`stat.S_ISUID` |
| 1427 | * :data:`stat.S_ISGID` |
| 1428 | * :data:`stat.S_ENFMT` |
| 1429 | * :data:`stat.S_ISVTX` |
| 1430 | * :data:`stat.S_IREAD` |
| 1431 | * :data:`stat.S_IWRITE` |
| 1432 | * :data:`stat.S_IEXEC` |
| 1433 | * :data:`stat.S_IRWXU` |
| 1434 | * :data:`stat.S_IRUSR` |
| 1435 | * :data:`stat.S_IWUSR` |
| 1436 | * :data:`stat.S_IXUSR` |
| 1437 | * :data:`stat.S_IRWXG` |
| 1438 | * :data:`stat.S_IRGRP` |
| 1439 | * :data:`stat.S_IWGRP` |
| 1440 | * :data:`stat.S_IXGRP` |
| 1441 | * :data:`stat.S_IRWXO` |
| 1442 | * :data:`stat.S_IROTH` |
| 1443 | * :data:`stat.S_IWOTH` |
| 1444 | * :data:`stat.S_IXOTH` |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1445 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1446 | This function can support :ref:`specifying a file descriptor <path_fd>`, |
| 1447 | :ref:`paths relative to directory descriptors <dir_fd>` and :ref:`not |
| 1448 | following symlinks <follow_symlinks>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1449 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 1450 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1451 | |
| 1452 | .. note:: |
| 1453 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1454 | Although Windows supports :func:`chmod`, you can only set the file's |
| 1455 | read-only flag with it (via the ``stat.S_IWRITE`` and ``stat.S_IREAD`` |
| 1456 | constants or a corresponding integer value). All other bits are ignored. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1457 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1458 | .. versionadded:: 3.3 |
| 1459 | Added support for specifying *path* as an open file descriptor, |
| 1460 | and the *dir_fd* and *follow_symlinks* arguments. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1461 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1462 | |
| 1463 | .. function:: chown(path, uid, gid, *, dir_fd=None, follow_symlinks=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1464 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1465 | Change the owner and group id of *path* to the numeric *uid* and *gid*. To |
| 1466 | leave one of the ids unchanged, set it to -1. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1467 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1468 | This function can support :ref:`specifying a file descriptor <path_fd>`, |
| 1469 | :ref:`paths relative to directory descriptors <dir_fd>` and :ref:`not |
| 1470 | following symlinks <follow_symlinks>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1471 | |
Sandro Tosi | d902a14 | 2011-08-22 23:28:27 +0200 | [diff] [blame] | 1472 | See :func:`shutil.chown` for a higher-level function that accepts names in |
| 1473 | addition to numeric ids. |
| 1474 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1475 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1476 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1477 | .. versionadded:: 3.3 |
| 1478 | Added support for specifying an open file descriptor for *path*, |
| 1479 | and the *dir_fd* and *follow_symlinks* arguments. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1480 | |
Benjamin Peterson | 799bd80 | 2011-08-31 22:15:17 -0400 | [diff] [blame] | 1481 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1482 | .. function:: chroot(path) |
| 1483 | |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 1484 | Change the root directory of the current process to *path*. |
| 1485 | |
| 1486 | Availability: Unix. |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1487 | |
| 1488 | |
| 1489 | .. function:: fchdir(fd) |
| 1490 | |
| 1491 | Change the current working directory to the directory represented by the file |
| 1492 | descriptor *fd*. The descriptor must refer to an opened directory, not an |
Georg Brandl | 4d399a4 | 2012-06-25 07:40:32 +0200 | [diff] [blame] | 1493 | open file. As of Python 3.3, this is equivalent to ``os.chdir(fd)``. |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1494 | |
| 1495 | Availability: Unix. |
| 1496 | |
| 1497 | |
| 1498 | .. function:: getcwd() |
| 1499 | |
| 1500 | Return a string representing the current working directory. |
| 1501 | |
| 1502 | Availability: Unix, Windows. |
| 1503 | |
| 1504 | |
| 1505 | .. function:: getcwdb() |
| 1506 | |
| 1507 | Return a bytestring representing the current working directory. |
| 1508 | |
| 1509 | Availability: Unix, Windows. |
| 1510 | |
| 1511 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1512 | .. function:: lchflags(path, flags) |
| 1513 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1514 | Set the flags of *path* to the numeric *flags*, like :func:`chflags`, but do |
Georg Brandl | 4d399a4 | 2012-06-25 07:40:32 +0200 | [diff] [blame] | 1515 | not follow symbolic links. As of Python 3.3, this is equivalent to |
Georg Brandl | b9df00c | 2012-06-24 12:38:14 +0200 | [diff] [blame] | 1516 | ``os.chflags(path, flags, follow_symlinks=False)``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1517 | |
| 1518 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1519 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1520 | |
Christian Heimes | 9385266 | 2007-12-01 12:22:32 +0000 | [diff] [blame] | 1521 | .. function:: lchmod(path, mode) |
| 1522 | |
| 1523 | Change the mode of *path* to the numeric *mode*. If path is a symlink, this |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1524 | affects the symlink rather than the target. See the docs for :func:`chmod` |
Georg Brandl | 4d399a4 | 2012-06-25 07:40:32 +0200 | [diff] [blame] | 1525 | for possible values of *mode*. As of Python 3.3, this is equivalent to |
Georg Brandl | b9df00c | 2012-06-24 12:38:14 +0200 | [diff] [blame] | 1526 | ``os.chmod(path, mode, follow_symlinks=False)``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1527 | |
| 1528 | Availability: Unix. |
Christian Heimes | 9385266 | 2007-12-01 12:22:32 +0000 | [diff] [blame] | 1529 | |
Christian Heimes | 9385266 | 2007-12-01 12:22:32 +0000 | [diff] [blame] | 1530 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1531 | .. function:: lchown(path, uid, gid) |
| 1532 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1533 | Change the owner and group id of *path* to the numeric *uid* and *gid*. This |
Georg Brandl | 4d399a4 | 2012-06-25 07:40:32 +0200 | [diff] [blame] | 1534 | function will not follow symbolic links. As of Python 3.3, this is equivalent |
Georg Brandl | b9df00c | 2012-06-24 12:38:14 +0200 | [diff] [blame] | 1535 | to ``os.chown(path, uid, gid, follow_symlinks=False)``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1536 | |
| 1537 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1538 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1539 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1540 | .. function:: link(src, dst, *, src_dir_fd=None, dst_dir_fd=None, follow_symlinks=True) |
Benjamin Peterson | 799bd80 | 2011-08-31 22:15:17 -0400 | [diff] [blame] | 1541 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1542 | Create a hard link pointing to *src* named *dst*. |
Benjamin Peterson | 799bd80 | 2011-08-31 22:15:17 -0400 | [diff] [blame] | 1543 | |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 1544 | This function can support specifying *src_dir_fd* and/or *dst_dir_fd* to |
| 1545 | supply :ref:`paths relative to directory descriptors <dir_fd>`, and :ref:`not |
| 1546 | following symlinks <follow_symlinks>`. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1547 | |
Brian Curtin | 1b9df39 | 2010-11-24 20:24:31 +0000 | [diff] [blame] | 1548 | Availability: Unix, Windows. |
| 1549 | |
| 1550 | .. versionchanged:: 3.2 |
| 1551 | Added Windows support. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1552 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1553 | .. versionadded:: 3.3 |
| 1554 | Added the *src_dir_fd*, *dst_dir_fd*, and *follow_symlinks* arguments. |
| 1555 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1556 | |
Martin v. Löwis | 9c71f90 | 2010-07-24 10:09:11 +0000 | [diff] [blame] | 1557 | .. function:: listdir(path='.') |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1558 | |
Benjamin Peterson | 4469d0c | 2008-11-30 22:46:23 +0000 | [diff] [blame] | 1559 | Return a list containing the names of the entries in the directory given by |
Larry Hastings | fdaea06 | 2012-06-25 04:42:23 -0700 | [diff] [blame] | 1560 | *path*. The list is in arbitrary order, and does not include the special |
| 1561 | entries ``'.'`` and ``'..'`` even if they are present in the directory. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1562 | |
Larry Hastings | fdaea06 | 2012-06-25 04:42:23 -0700 | [diff] [blame] | 1563 | *path* may be either of type ``str`` or of type ``bytes``. If *path* |
| 1564 | is of type ``bytes``, the filenames returned will also be of type ``bytes``; |
| 1565 | in all other circumstances, they will be of type ``str``. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1566 | |
Larry Hastings | 77892dc | 2012-06-25 03:27:33 -0700 | [diff] [blame] | 1567 | This function can also support :ref:`specifying a file descriptor |
| 1568 | <path_fd>`; the file descriptor must refer to a directory. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1569 | |
Larry Hastings | fdaea06 | 2012-06-25 04:42:23 -0700 | [diff] [blame] | 1570 | .. note:: |
| 1571 | To encode ``str`` filenames to ``bytes``, use :func:`~os.fsencode`. |
| 1572 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1573 | Availability: Unix, Windows. |
| 1574 | |
Martin v. Löwis | c9e1c7d | 2010-07-23 12:16:41 +0000 | [diff] [blame] | 1575 | .. versionchanged:: 3.2 |
| 1576 | The *path* parameter became optional. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1577 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1578 | .. versionadded:: 3.3 |
| 1579 | Added support for specifying an open file descriptor for *path*. |
Benjamin Peterson | 799bd80 | 2011-08-31 22:15:17 -0400 | [diff] [blame] | 1580 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1581 | |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 1582 | .. function:: lstat(path, \*, dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1583 | |
R. David Murray | 7b1aae9 | 2011-01-24 19:34:58 +0000 | [diff] [blame] | 1584 | Perform the equivalent of an :c:func:`lstat` system call on the given path. |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 1585 | Similar to :func:`~os.stat`, but does not follow symbolic links. Return a |
| 1586 | :class:`stat_result` object. |
| 1587 | |
| 1588 | On platforms that do not support symbolic links, this is an alias for |
| 1589 | :func:`~os.stat`. |
| 1590 | |
| 1591 | As of Python 3.3, this is equivalent to ``os.stat(path, dir_fd=dir_fd, |
| 1592 | follow_symlinks=False)``. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1593 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1594 | This function can also support :ref:`paths relative to directory descriptors |
| 1595 | <dir_fd>`. |
Brian Curtin | c739569 | 2010-07-09 15:15:09 +0000 | [diff] [blame] | 1596 | |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 1597 | .. seealso:: |
| 1598 | |
Berker Peksag | 2034caa | 2015-04-27 13:53:28 +0300 | [diff] [blame] | 1599 | The :func:`.stat` function. |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 1600 | |
Georg Brandl | b382337 | 2010-07-10 08:58:37 +0000 | [diff] [blame] | 1601 | .. versionchanged:: 3.2 |
| 1602 | Added support for Windows 6.0 (Vista) symbolic links. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1603 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1604 | .. versionchanged:: 3.3 |
| 1605 | Added the *dir_fd* parameter. |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 1606 | |
| 1607 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1608 | .. function:: mkdir(path, mode=0o777, *, dir_fd=None) |
| 1609 | |
| 1610 | Create a directory named *path* with numeric mode *mode*. |
| 1611 | |
| 1612 | On some systems, *mode* is ignored. Where it is used, the current umask |
| 1613 | value is first masked out. If the directory already exists, :exc:`OSError` |
| 1614 | is raised. |
| 1615 | |
| 1616 | This function can also support :ref:`paths relative to directory descriptors |
| 1617 | <dir_fd>`. |
| 1618 | |
| 1619 | It is also possible to create temporary directories; see the |
| 1620 | :mod:`tempfile` module's :func:`tempfile.mkdtemp` function. |
| 1621 | |
| 1622 | Availability: Unix, Windows. |
| 1623 | |
| 1624 | .. versionadded:: 3.3 |
| 1625 | The *dir_fd* argument. |
| 1626 | |
| 1627 | |
Zachary Ware | a22ae21 | 2014-03-20 09:42:01 -0500 | [diff] [blame] | 1628 | .. function:: makedirs(name, mode=0o777, exist_ok=False) |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1629 | |
| 1630 | .. index:: |
| 1631 | single: directory; creating |
| 1632 | single: UNC paths; and os.makedirs() |
| 1633 | |
| 1634 | Recursive directory creation function. Like :func:`mkdir`, but makes all |
Hynek Schlawack | 0230b6a | 2012-10-07 18:04:38 +0200 | [diff] [blame] | 1635 | intermediate-level directories needed to contain the leaf directory. |
| 1636 | |
| 1637 | The default *mode* is ``0o777`` (octal). On some systems, *mode* is |
| 1638 | ignored. Where it is used, the current umask value is first masked out. |
| 1639 | |
Benjamin Peterson | ee5f1c1 | 2014-04-01 19:13:18 -0400 | [diff] [blame] | 1640 | If *exist_ok* is ``False`` (the default), an :exc:`OSError` is raised if the |
| 1641 | target directory already exists. |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1642 | |
| 1643 | .. note:: |
| 1644 | |
| 1645 | :func:`makedirs` will become confused if the path elements to create |
Hynek Schlawack | 0230b6a | 2012-10-07 18:04:38 +0200 | [diff] [blame] | 1646 | include :data:`pardir` (eg. ".." on UNIX systems). |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1647 | |
| 1648 | This function handles UNC paths correctly. |
| 1649 | |
| 1650 | .. versionadded:: 3.2 |
| 1651 | The *exist_ok* parameter. |
| 1652 | |
Benjamin Peterson | 1acc69c | 2014-04-01 19:22:06 -0400 | [diff] [blame] | 1653 | .. versionchanged:: 3.4.1 |
Benjamin Peterson | ee5f1c1 | 2014-04-01 19:13:18 -0400 | [diff] [blame] | 1654 | |
Benjamin Peterson | 1acc69c | 2014-04-01 19:22:06 -0400 | [diff] [blame] | 1655 | Before Python 3.4.1, if *exist_ok* was ``True`` and the directory existed, |
Benjamin Peterson | ee5f1c1 | 2014-04-01 19:13:18 -0400 | [diff] [blame] | 1656 | :func:`makedirs` would still raise an error if *mode* did not match the |
| 1657 | mode of the existing directory. Since this behavior was impossible to |
Benjamin Peterson | 1acc69c | 2014-04-01 19:22:06 -0400 | [diff] [blame] | 1658 | implement safely, it was removed in Python 3.4.1. See :issue:`21082`. |
Benjamin Peterson | 4717e21 | 2014-04-01 19:17:57 -0400 | [diff] [blame] | 1659 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1660 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1661 | .. function:: mkfifo(path, mode=0o666, *, dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1662 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1663 | Create a FIFO (a named pipe) named *path* with numeric mode *mode*. |
| 1664 | The current umask value is first masked out from the mode. |
| 1665 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1666 | This function can also support :ref:`paths relative to directory descriptors |
| 1667 | <dir_fd>`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1668 | |
| 1669 | FIFOs are pipes that can be accessed like regular files. FIFOs exist until they |
| 1670 | are deleted (for example with :func:`os.unlink`). Generally, FIFOs are used as |
| 1671 | rendezvous between "client" and "server" type processes: the server opens the |
| 1672 | FIFO for reading, and the client opens it for writing. Note that :func:`mkfifo` |
| 1673 | doesn't open the FIFO --- it just creates the rendezvous point. |
| 1674 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1675 | Availability: Unix. |
| 1676 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1677 | .. versionadded:: 3.3 |
| 1678 | The *dir_fd* argument. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1679 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1680 | |
Martin Panter | bf19d16 | 2015-09-09 01:01:13 +0000 | [diff] [blame] | 1681 | .. function:: mknod(path, mode=0o600, device=0, *, dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1682 | |
| 1683 | Create a filesystem node (file, device special file or named pipe) named |
Martin Panter | bf19d16 | 2015-09-09 01:01:13 +0000 | [diff] [blame] | 1684 | *path*. *mode* specifies both the permissions to use and the type of node |
Georg Brandl | 1824415 | 2009-09-02 20:34:52 +0000 | [diff] [blame] | 1685 | to be created, being combined (bitwise OR) with one of ``stat.S_IFREG``, |
| 1686 | ``stat.S_IFCHR``, ``stat.S_IFBLK``, and ``stat.S_IFIFO`` (those constants are |
| 1687 | available in :mod:`stat`). For ``stat.S_IFCHR`` and ``stat.S_IFBLK``, |
| 1688 | *device* defines the newly created device special file (probably using |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1689 | :func:`os.makedev`), otherwise it is ignored. |
| 1690 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1691 | This function can also support :ref:`paths relative to directory descriptors |
| 1692 | <dir_fd>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1693 | |
| 1694 | .. versionadded:: 3.3 |
| 1695 | The *dir_fd* argument. |
| 1696 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1697 | |
| 1698 | .. function:: major(device) |
| 1699 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 1700 | Extract the device major number from a raw device number (usually the |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 1701 | :attr:`st_dev` or :attr:`st_rdev` field from :c:type:`stat`). |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1702 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1703 | |
| 1704 | .. function:: minor(device) |
| 1705 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 1706 | Extract the device minor number from a raw device number (usually the |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 1707 | :attr:`st_dev` or :attr:`st_rdev` field from :c:type:`stat`). |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1708 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1709 | |
| 1710 | .. function:: makedev(major, minor) |
| 1711 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 1712 | Compose a raw device number from the major and minor device numbers. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1713 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1714 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1715 | .. function:: pathconf(path, name) |
| 1716 | |
| 1717 | Return system configuration information relevant to a named file. *name* |
| 1718 | specifies the configuration value to retrieve; it may be a string which is the |
| 1719 | name of a defined system value; these names are specified in a number of |
| 1720 | standards (POSIX.1, Unix 95, Unix 98, and others). Some platforms define |
| 1721 | additional names as well. The names known to the host operating system are |
| 1722 | given in the ``pathconf_names`` dictionary. For configuration variables not |
| 1723 | included in that mapping, passing an integer for *name* is also accepted. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1724 | |
| 1725 | If *name* is a string and is not known, :exc:`ValueError` is raised. If a |
| 1726 | specific value for *name* is not supported by the host system, even if it is |
| 1727 | included in ``pathconf_names``, an :exc:`OSError` is raised with |
| 1728 | :const:`errno.EINVAL` for the error number. |
| 1729 | |
Larry Hastings | 77892dc | 2012-06-25 03:27:33 -0700 | [diff] [blame] | 1730 | This function can support :ref:`specifying a file descriptor |
Georg Brandl | 306336b | 2012-06-24 12:55:33 +0200 | [diff] [blame] | 1731 | <path_fd>`. |
| 1732 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1733 | Availability: Unix. |
| 1734 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1735 | |
| 1736 | .. data:: pathconf_names |
| 1737 | |
| 1738 | Dictionary mapping names accepted by :func:`pathconf` and :func:`fpathconf` to |
| 1739 | the integer values defined for those names by the host operating system. This |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 1740 | can be used to determine the set of names known to the system. |
| 1741 | |
| 1742 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1743 | |
| 1744 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1745 | .. function:: readlink(path, *, dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1746 | |
| 1747 | Return a string representing the path to which the symbolic link points. The |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1748 | result may be either an absolute or relative pathname; if it is relative, it |
| 1749 | may be converted to an absolute pathname using |
| 1750 | ``os.path.join(os.path.dirname(path), result)``. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1751 | |
Georg Brandl | 76e5538 | 2008-10-08 16:34:57 +0000 | [diff] [blame] | 1752 | If the *path* is a string object, the result will also be a string object, |
| 1753 | and the call may raise an UnicodeDecodeError. If the *path* is a bytes |
| 1754 | object, the result will be a bytes object. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1755 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1756 | This function can also support :ref:`paths relative to directory descriptors |
| 1757 | <dir_fd>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1758 | |
Brian Curtin | c739569 | 2010-07-09 15:15:09 +0000 | [diff] [blame] | 1759 | Availability: Unix, Windows |
| 1760 | |
Georg Brandl | b382337 | 2010-07-10 08:58:37 +0000 | [diff] [blame] | 1761 | .. versionchanged:: 3.2 |
| 1762 | Added support for Windows 6.0 (Vista) symbolic links. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1763 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1764 | .. versionadded:: 3.3 |
| 1765 | The *dir_fd* argument. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1766 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1767 | |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 1768 | .. function:: remove(path, *, dir_fd=None) |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1769 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1770 | Remove (delete) the file *path*. If *path* is a directory, :exc:`OSError` is |
| 1771 | raised. Use :func:`rmdir` to remove directories. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1772 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1773 | This function can support :ref:`paths relative to directory descriptors |
| 1774 | <dir_fd>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1775 | |
| 1776 | On Windows, attempting to remove a file that is in use causes an exception to |
| 1777 | be raised; on Unix, the directory entry is removed but the storage allocated |
| 1778 | to the file is not made available until the original file is no longer in use. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1779 | |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 1780 | This function is identical to :func:`unlink`. |
| 1781 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1782 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1783 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1784 | .. versionadded:: 3.3 |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 1785 | The *dir_fd* argument. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1786 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1787 | |
Zachary Ware | a22ae21 | 2014-03-20 09:42:01 -0500 | [diff] [blame] | 1788 | .. function:: removedirs(name) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1789 | |
| 1790 | .. index:: single: directory; deleting |
| 1791 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 1792 | Remove directories recursively. Works like :func:`rmdir` except that, if the |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1793 | leaf directory is successfully removed, :func:`removedirs` tries to |
| 1794 | successively remove every parent directory mentioned in *path* until an error |
| 1795 | is raised (which is ignored, because it generally means that a parent directory |
| 1796 | is not empty). For example, ``os.removedirs('foo/bar/baz')`` will first remove |
| 1797 | the directory ``'foo/bar/baz'``, and then remove ``'foo/bar'`` and ``'foo'`` if |
| 1798 | they are empty. Raises :exc:`OSError` if the leaf directory could not be |
| 1799 | successfully removed. |
| 1800 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1801 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1802 | .. function:: rename(src, dst, *, src_dir_fd=None, dst_dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1803 | |
| 1804 | Rename the file or directory *src* to *dst*. If *dst* is a directory, |
| 1805 | :exc:`OSError` will be raised. On Unix, if *dst* exists and is a file, it will |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 1806 | be replaced silently if the user has permission. The operation may fail on some |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1807 | Unix flavors if *src* and *dst* are on different filesystems. If successful, |
| 1808 | the renaming will be an atomic operation (this is a POSIX requirement). On |
| 1809 | Windows, if *dst* already exists, :exc:`OSError` will be raised even if it is a |
Antoine Pitrou | f3b2d88 | 2012-01-30 22:08:52 +0100 | [diff] [blame] | 1810 | file. |
| 1811 | |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 1812 | This function can support specifying *src_dir_fd* and/or *dst_dir_fd* to |
| 1813 | supply :ref:`paths relative to directory descriptors <dir_fd>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1814 | |
Antoine Pitrou | f3b2d88 | 2012-01-30 22:08:52 +0100 | [diff] [blame] | 1815 | If you want cross-platform overwriting of the destination, use :func:`replace`. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1816 | |
| 1817 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1818 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1819 | .. versionadded:: 3.3 |
| 1820 | The *src_dir_fd* and *dst_dir_fd* arguments. |
| 1821 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1822 | |
| 1823 | .. function:: renames(old, new) |
| 1824 | |
| 1825 | Recursive directory or file renaming function. Works like :func:`rename`, except |
| 1826 | creation of any intermediate directories needed to make the new pathname good is |
| 1827 | attempted first. After the rename, directories corresponding to rightmost path |
| 1828 | segments of the old name will be pruned away using :func:`removedirs`. |
| 1829 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1830 | .. note:: |
| 1831 | |
| 1832 | This function can fail with the new directory structure made if you lack |
| 1833 | permissions needed to remove the leaf directory or file. |
| 1834 | |
| 1835 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1836 | .. function:: replace(src, dst, *, src_dir_fd=None, dst_dir_fd=None) |
Antoine Pitrou | f3b2d88 | 2012-01-30 22:08:52 +0100 | [diff] [blame] | 1837 | |
| 1838 | Rename the file or directory *src* to *dst*. If *dst* is a directory, |
| 1839 | :exc:`OSError` will be raised. If *dst* exists and is a file, it will |
| 1840 | be replaced silently if the user has permission. The operation may fail |
| 1841 | if *src* and *dst* are on different filesystems. If successful, |
| 1842 | the renaming will be an atomic operation (this is a POSIX requirement). |
| 1843 | |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 1844 | This function can support specifying *src_dir_fd* and/or *dst_dir_fd* to |
| 1845 | supply :ref:`paths relative to directory descriptors <dir_fd>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1846 | |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 1847 | Availability: Unix, Windows. |
Antoine Pitrou | f3b2d88 | 2012-01-30 22:08:52 +0100 | [diff] [blame] | 1848 | |
| 1849 | .. versionadded:: 3.3 |
| 1850 | |
| 1851 | |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 1852 | .. function:: rmdir(path, *, dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1853 | |
Georg Brandl | a6053b4 | 2009-09-01 08:11:14 +0000 | [diff] [blame] | 1854 | Remove (delete) the directory *path*. Only works when the directory is |
| 1855 | empty, otherwise, :exc:`OSError` is raised. In order to remove whole |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1856 | directory trees, :func:`shutil.rmtree` can be used. |
| 1857 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1858 | This function can support :ref:`paths relative to directory descriptors |
| 1859 | <dir_fd>`. |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 1860 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1861 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1862 | |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 1863 | .. versionadded:: 3.3 |
| 1864 | The *dir_fd* parameter. |
| 1865 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1866 | |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 1867 | .. function:: stat(path, \*, dir_fd=None, follow_symlinks=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1868 | |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 1869 | Get the status of a file or a file descriptor. Perform the equivalent of a |
| 1870 | :c:func:`stat` system call on the given path. *path* may be specified as |
| 1871 | either a string or as an open file descriptor. Return a :class:`stat_result` |
| 1872 | object. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1873 | |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 1874 | This function normally follows symlinks; to stat a symlink add the argument |
| 1875 | ``follow_symlinks=False``, or use :func:`lstat`. |
R. David Murray | 7b1aae9 | 2011-01-24 19:34:58 +0000 | [diff] [blame] | 1876 | |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 1877 | This function can support :ref:`specifying a file descriptor <path_fd>` and |
| 1878 | :ref:`not following symlinks <follow_symlinks>`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1879 | |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 1880 | .. index:: module: stat |
R. David Murray | 7b1aae9 | 2011-01-24 19:34:58 +0000 | [diff] [blame] | 1881 | |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 1882 | Example:: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1883 | |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 1884 | >>> import os |
| 1885 | >>> statinfo = os.stat('somefile.txt') |
| 1886 | >>> statinfo |
| 1887 | os.stat_result(st_mode=33188, st_ino=7876932, st_dev=234881026, |
| 1888 | st_nlink=1, st_uid=501, st_gid=501, st_size=264, st_atime=1297230295, |
| 1889 | st_mtime=1297230027, st_ctime=1297230027) |
| 1890 | >>> statinfo.st_size |
| 1891 | 264 |
R. David Murray | 7b1aae9 | 2011-01-24 19:34:58 +0000 | [diff] [blame] | 1892 | |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 1893 | Availability: Unix, Windows. |
| 1894 | |
| 1895 | .. seealso:: |
| 1896 | |
| 1897 | :func:`fstat` and :func:`lstat` functions. |
| 1898 | |
| 1899 | .. versionadded:: 3.3 |
| 1900 | Added the *dir_fd* and *follow_symlinks* arguments, specifying a file |
| 1901 | descriptor instead of a path. |
| 1902 | |
| 1903 | |
| 1904 | .. class:: stat_result |
| 1905 | |
| 1906 | Object whose attributes correspond roughly to the members of the |
| 1907 | :c:type:`stat` structure. It is used for the result of :func:`os.stat`, |
| 1908 | :func:`os.fstat` and :func:`os.lstat`. |
| 1909 | |
| 1910 | Attributes: |
| 1911 | |
| 1912 | .. attribute:: st_mode |
| 1913 | |
| 1914 | File mode: file type and file mode bits (permissions). |
| 1915 | |
| 1916 | .. attribute:: st_ino |
| 1917 | |
| 1918 | Inode number. |
| 1919 | |
| 1920 | .. attribute:: st_dev |
| 1921 | |
| 1922 | Identifier of the device on which this file resides. |
| 1923 | |
| 1924 | .. attribute:: st_nlink |
| 1925 | |
| 1926 | Number of hard links. |
| 1927 | |
| 1928 | .. attribute:: st_uid |
| 1929 | |
| 1930 | User identifier of the file owner. |
| 1931 | |
| 1932 | .. attribute:: st_gid |
| 1933 | |
| 1934 | Group identifier of the file owner. |
| 1935 | |
| 1936 | .. attribute:: st_size |
| 1937 | |
| 1938 | Size of the file in bytes, if it is a regular file or a symbolic link. |
| 1939 | The size of a symbolic link is the length of the pathname it contains, |
| 1940 | without a terminating null byte. |
| 1941 | |
| 1942 | Timestamps: |
| 1943 | |
| 1944 | .. attribute:: st_atime |
| 1945 | |
| 1946 | Time of most recent access expressed in seconds. |
| 1947 | |
| 1948 | .. attribute:: st_mtime |
| 1949 | |
| 1950 | Time of most recent content modification expressed in seconds. |
| 1951 | |
| 1952 | .. attribute:: st_ctime |
| 1953 | |
| 1954 | Platform dependent: |
| 1955 | |
| 1956 | * the time of most recent metadata change on Unix, |
| 1957 | * the time of creation on Windows, expressed in seconds. |
| 1958 | |
| 1959 | .. attribute:: st_atime_ns |
| 1960 | |
| 1961 | Time of most recent access expressed in nanoseconds as an integer. |
| 1962 | |
| 1963 | .. attribute:: st_mtime_ns |
| 1964 | |
| 1965 | Time of most recent content modification expressed in nanoseconds as an |
| 1966 | integer. |
| 1967 | |
| 1968 | .. attribute:: st_ctime_ns |
| 1969 | |
| 1970 | Platform dependent: |
| 1971 | |
| 1972 | * the time of most recent metadata change on Unix, |
| 1973 | * the time of creation on Windows, expressed in nanoseconds as an |
| 1974 | integer. |
| 1975 | |
| 1976 | See also the :func:`stat_float_times` function. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1977 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1978 | .. note:: |
| 1979 | |
Senthil Kumaran | 3aac179 | 2011-07-04 11:43:51 -0700 | [diff] [blame] | 1980 | The exact meaning and resolution of the :attr:`st_atime`, |
Senthil Kumaran | a6bac95 | 2011-07-04 11:28:30 -0700 | [diff] [blame] | 1981 | :attr:`st_mtime`, and :attr:`st_ctime` attributes depend on the operating |
| 1982 | system and the file system. For example, on Windows systems using the FAT |
| 1983 | or FAT32 file systems, :attr:`st_mtime` has 2-second resolution, and |
| 1984 | :attr:`st_atime` has only 1-day resolution. See your operating system |
| 1985 | documentation for details. |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 1986 | |
Larry Hastings | 6fe20b3 | 2012-04-19 15:07:49 -0700 | [diff] [blame] | 1987 | Similarly, although :attr:`st_atime_ns`, :attr:`st_mtime_ns`, |
| 1988 | and :attr:`st_ctime_ns` are always expressed in nanoseconds, many |
| 1989 | systems do not provide nanosecond precision. On systems that do |
| 1990 | provide nanosecond precision, the floating-point object used to |
| 1991 | store :attr:`st_atime`, :attr:`st_mtime`, and :attr:`st_ctime` |
| 1992 | cannot preserve all of it, and as such will be slightly inexact. |
| 1993 | If you need the exact timestamps you should always use |
| 1994 | :attr:`st_atime_ns`, :attr:`st_mtime_ns`, and :attr:`st_ctime_ns`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1995 | |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 1996 | On some Unix systems (such as Linux), the following attributes may also be |
| 1997 | available: |
| 1998 | |
| 1999 | .. attribute:: st_blocks |
| 2000 | |
| 2001 | Number of 512-byte blocks allocated for file. |
| 2002 | This may be smaller than :attr:`st_size`/512 when the file has holes. |
| 2003 | |
| 2004 | .. attribute:: st_blksize |
| 2005 | |
| 2006 | "Preferred" blocksize for efficient file system I/O. Writing to a file in |
| 2007 | smaller chunks may cause an inefficient read-modify-rewrite. |
| 2008 | |
| 2009 | .. attribute:: st_rdev |
| 2010 | |
| 2011 | Type of device if an inode device. |
| 2012 | |
| 2013 | .. attribute:: st_flags |
| 2014 | |
| 2015 | User defined flags for file. |
| 2016 | |
| 2017 | On other Unix systems (such as FreeBSD), the following attributes may be |
| 2018 | available (but may be only filled out if root tries to use them): |
| 2019 | |
| 2020 | .. attribute:: st_gen |
| 2021 | |
| 2022 | File generation number. |
| 2023 | |
| 2024 | .. attribute:: st_birthtime |
| 2025 | |
| 2026 | Time of file creation. |
| 2027 | |
| 2028 | On Mac OS systems, the following attributes may also be available: |
| 2029 | |
| 2030 | .. attribute:: st_rsize |
| 2031 | |
| 2032 | Real size of the file. |
| 2033 | |
| 2034 | .. attribute:: st_creator |
| 2035 | |
| 2036 | Creator of the file. |
| 2037 | |
| 2038 | .. attribute:: st_type |
| 2039 | |
| 2040 | File type. |
| 2041 | |
| 2042 | The standard module :mod:`stat` defines functions and constants that are |
| 2043 | useful for extracting information from a :c:type:`stat` structure. (On |
| 2044 | Windows, some items are filled with dummy values.) |
| 2045 | |
| 2046 | For backward compatibility, a :class:`stat_result` instance is also |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 2047 | accessible as a tuple of at least 10 integers giving the most important (and |
| 2048 | portable) members of the :c:type:`stat` structure, in the order |
| 2049 | :attr:`st_mode`, :attr:`st_ino`, :attr:`st_dev`, :attr:`st_nlink`, |
| 2050 | :attr:`st_uid`, :attr:`st_gid`, :attr:`st_size`, :attr:`st_atime`, |
| 2051 | :attr:`st_mtime`, :attr:`st_ctime`. More items may be added at the end by |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 2052 | some implementations. For compatibility with older Python versions, |
| 2053 | accessing :class:`stat_result` as a tuple always returns integers. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2054 | |
Larry Hastings | 6fe20b3 | 2012-04-19 15:07:49 -0700 | [diff] [blame] | 2055 | .. versionadded:: 3.3 |
Victor Stinner | 6d4f4fe | 2014-07-24 12:42:16 +0200 | [diff] [blame] | 2056 | Added the :attr:`st_atime_ns`, :attr:`st_mtime_ns`, and |
| 2057 | :attr:`st_ctime_ns` members. |
Larry Hastings | 6fe20b3 | 2012-04-19 15:07:49 -0700 | [diff] [blame] | 2058 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2059 | |
| 2060 | .. function:: stat_float_times([newvalue]) |
| 2061 | |
| 2062 | Determine whether :class:`stat_result` represents time stamps as float objects. |
R. David Murray | 7b1aae9 | 2011-01-24 19:34:58 +0000 | [diff] [blame] | 2063 | If *newvalue* is ``True``, future calls to :func:`~os.stat` return floats, if it is |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2064 | ``False``, future calls return ints. If *newvalue* is omitted, return the |
| 2065 | current setting. |
| 2066 | |
| 2067 | For compatibility with older Python versions, accessing :class:`stat_result` as |
| 2068 | a tuple always returns integers. |
| 2069 | |
Georg Brandl | 55ac8f0 | 2007-09-01 13:51:09 +0000 | [diff] [blame] | 2070 | Python now returns float values by default. Applications which do not work |
| 2071 | correctly with floating point time stamps can use this function to restore the |
| 2072 | old behaviour. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2073 | |
| 2074 | The resolution of the timestamps (that is the smallest possible fraction) |
| 2075 | depends on the system. Some systems only support second resolution; on these |
| 2076 | systems, the fraction will always be zero. |
| 2077 | |
| 2078 | It is recommended that this setting is only changed at program startup time in |
| 2079 | the *__main__* module; libraries should never change this setting. If an |
| 2080 | application uses a library that works incorrectly if floating point time stamps |
| 2081 | are processed, this application should turn the feature off until the library |
| 2082 | has been corrected. |
| 2083 | |
Victor Stinner | 034d0aa | 2012-06-05 01:22:15 +0200 | [diff] [blame] | 2084 | .. deprecated:: 3.3 |
| 2085 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2086 | |
| 2087 | .. function:: statvfs(path) |
| 2088 | |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 2089 | Perform a :c:func:`statvfs` system call on the given path. The return value is |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2090 | an object whose attributes describe the filesystem on the given path, and |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 2091 | correspond to the members of the :c:type:`statvfs` structure, namely: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2092 | :attr:`f_bsize`, :attr:`f_frsize`, :attr:`f_blocks`, :attr:`f_bfree`, |
| 2093 | :attr:`f_bavail`, :attr:`f_files`, :attr:`f_ffree`, :attr:`f_favail`, |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2094 | :attr:`f_flag`, :attr:`f_namemax`. |
| 2095 | |
Andrew M. Kuchling | 4ea04a3 | 2010-08-18 22:30:34 +0000 | [diff] [blame] | 2096 | Two module-level constants are defined for the :attr:`f_flag` attribute's |
| 2097 | bit-flags: if :const:`ST_RDONLY` is set, the filesystem is mounted |
| 2098 | read-only, and if :const:`ST_NOSUID` is set, the semantics of |
| 2099 | setuid/setgid bits are disabled or not supported. |
| 2100 | |
doko@ubuntu.com | ca616a2 | 2013-12-08 15:23:07 +0100 | [diff] [blame] | 2101 | Additional module-level constants are defined for GNU/glibc based systems. |
| 2102 | These are :const:`ST_NODEV` (disallow access to device special files), |
| 2103 | :const:`ST_NOEXEC` (disallow program execution), :const:`ST_SYNCHRONOUS` |
| 2104 | (writes are synced at once), :const:`ST_MANDLOCK` (allow mandatory locks on an FS), |
| 2105 | :const:`ST_WRITE` (write on file/directory/symlink), :const:`ST_APPEND` |
| 2106 | (append-only file), :const:`ST_IMMUTABLE` (immutable file), :const:`ST_NOATIME` |
| 2107 | (do not update access times), :const:`ST_NODIRATIME` (do not update directory access |
| 2108 | times), :const:`ST_RELATIME` (update atime relative to mtime/ctime). |
| 2109 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 2110 | This function can support :ref:`specifying a file descriptor <path_fd>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2111 | |
Andrew M. Kuchling | 4ea04a3 | 2010-08-18 22:30:34 +0000 | [diff] [blame] | 2112 | .. versionchanged:: 3.2 |
| 2113 | The :const:`ST_RDONLY` and :const:`ST_NOSUID` constants were added. |
| 2114 | |
doko@ubuntu.com | ca616a2 | 2013-12-08 15:23:07 +0100 | [diff] [blame] | 2115 | .. versionchanged:: 3.4 |
| 2116 | The :const:`ST_NODEV`, :const:`ST_NOEXEC`, :const:`ST_SYNCHRONOUS`, |
| 2117 | :const:`ST_MANDLOCK`, :const:`ST_WRITE`, :const:`ST_APPEND`, |
| 2118 | :const:`ST_IMMUTABLE`, :const:`ST_NOATIME`, :const:`ST_NODIRATIME`, |
| 2119 | and :const:`ST_RELATIME` constants were added. |
| 2120 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2121 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2122 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2123 | .. versionadded:: 3.3 |
| 2124 | Added support for specifying an open file descriptor for *path*. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2125 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2126 | |
| 2127 | .. data:: supports_dir_fd |
| 2128 | |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 2129 | A :class:`~collections.abc.Set` object indicating which functions in the |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 2130 | :mod:`os` module permit use of their *dir_fd* parameter. Different platforms |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2131 | provide different functionality, and an option that might work on one might |
| 2132 | be unsupported on another. For consistency's sakes, functions that support |
Andrew Svetlov | 5b89840 | 2012-12-18 21:26:36 +0200 | [diff] [blame] | 2133 | *dir_fd* always allow specifying the parameter, but will raise an exception |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2134 | if the functionality is not actually available. |
| 2135 | |
| 2136 | To check whether a particular function permits use of its *dir_fd* |
| 2137 | parameter, use the ``in`` operator on ``supports_dir_fd``. As an example, |
| 2138 | this expression determines whether the *dir_fd* parameter of :func:`os.stat` |
| 2139 | is locally available:: |
| 2140 | |
| 2141 | os.stat in os.supports_dir_fd |
| 2142 | |
Georg Brandl | f62445a | 2012-06-24 13:31:20 +0200 | [diff] [blame] | 2143 | Currently *dir_fd* parameters only work on Unix platforms; none of them work |
| 2144 | on Windows. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2145 | |
| 2146 | .. versionadded:: 3.3 |
| 2147 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 2148 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2149 | .. data:: supports_effective_ids |
| 2150 | |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 2151 | A :class:`~collections.abc.Set` object indicating which functions in the |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 2152 | :mod:`os` module permit use of the *effective_ids* parameter for |
| 2153 | :func:`os.access`. If the local platform supports it, the collection will |
| 2154 | contain :func:`os.access`, otherwise it will be empty. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2155 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 2156 | To check whether you can use the *effective_ids* parameter for |
Berker Peksag | 4d6c606 | 2015-02-16 03:36:10 +0200 | [diff] [blame] | 2157 | :func:`os.access`, use the ``in`` operator on ``supports_effective_ids``, |
| 2158 | like so:: |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2159 | |
| 2160 | os.access in os.supports_effective_ids |
| 2161 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 2162 | Currently *effective_ids* only works on Unix platforms; it does not work on |
| 2163 | Windows. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2164 | |
| 2165 | .. versionadded:: 3.3 |
| 2166 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 2167 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2168 | .. data:: supports_fd |
| 2169 | |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 2170 | A :class:`~collections.abc.Set` object indicating which functions in the |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 2171 | :mod:`os` module permit specifying their *path* parameter as an open file |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2172 | descriptor. Different platforms provide different functionality, and an |
| 2173 | option that might work on one might be unsupported on another. For |
| 2174 | consistency's sakes, functions that support *fd* always allow specifying |
Andrew Svetlov | 5b89840 | 2012-12-18 21:26:36 +0200 | [diff] [blame] | 2175 | the parameter, but will raise an exception if the functionality is not |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2176 | actually available. |
| 2177 | |
| 2178 | To check whether a particular function permits specifying an open file |
| 2179 | descriptor for its *path* parameter, use the ``in`` operator on |
| 2180 | ``supports_fd``. As an example, this expression determines whether |
| 2181 | :func:`os.chdir` accepts open file descriptors when called on your local |
| 2182 | platform:: |
| 2183 | |
| 2184 | os.chdir in os.supports_fd |
| 2185 | |
| 2186 | .. versionadded:: 3.3 |
| 2187 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 2188 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2189 | .. data:: supports_follow_symlinks |
| 2190 | |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 2191 | A :class:`~collections.abc.Set` object indicating which functions in the |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 2192 | :mod:`os` module permit use of their *follow_symlinks* parameter. Different |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2193 | platforms provide different functionality, and an option that might work on |
| 2194 | one might be unsupported on another. For consistency's sakes, functions that |
| 2195 | support *follow_symlinks* always allow specifying the parameter, but will |
Andrew Svetlov | 5b89840 | 2012-12-18 21:26:36 +0200 | [diff] [blame] | 2196 | raise an exception if the functionality is not actually available. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2197 | |
| 2198 | To check whether a particular function permits use of its *follow_symlinks* |
| 2199 | parameter, use the ``in`` operator on ``supports_follow_symlinks``. As an |
| 2200 | example, this expression determines whether the *follow_symlinks* parameter |
| 2201 | of :func:`os.stat` is locally available:: |
| 2202 | |
| 2203 | os.stat in os.supports_follow_symlinks |
| 2204 | |
| 2205 | .. versionadded:: 3.3 |
| 2206 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 2207 | |
Martin Panter | bf19d16 | 2015-09-09 01:01:13 +0000 | [diff] [blame] | 2208 | .. function:: symlink(src, dst, target_is_directory=False, *, dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2209 | |
Martin Panter | bf19d16 | 2015-09-09 01:01:13 +0000 | [diff] [blame] | 2210 | Create a symbolic link pointing to *src* named *dst*. |
Brian Curtin | c739569 | 2010-07-09 15:15:09 +0000 | [diff] [blame] | 2211 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2212 | On Windows, a symlink represents either a file or a directory, and does not |
Jason R. Coombs | 3a09286 | 2013-05-27 23:21:28 -0400 | [diff] [blame] | 2213 | morph to the target dynamically. If the target is present, the type of the |
| 2214 | symlink will be created to match. Otherwise, the symlink will be created |
| 2215 | as a directory if *target_is_directory* is ``True`` or a file symlink (the |
| 2216 | default) otherwise. On non-Window platforms, *target_is_directory* is ignored. |
Brian Curtin | d40e6f7 | 2010-07-08 21:39:08 +0000 | [diff] [blame] | 2217 | |
Georg Brandl | 64a41ed | 2010-10-06 08:52:48 +0000 | [diff] [blame] | 2218 | Symbolic link support was introduced in Windows 6.0 (Vista). :func:`symlink` |
| 2219 | will raise a :exc:`NotImplementedError` on Windows versions earlier than 6.0. |
Brian Curtin | 52173d4 | 2010-12-02 18:29:18 +0000 | [diff] [blame] | 2220 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 2221 | This function can support :ref:`paths relative to directory descriptors |
| 2222 | <dir_fd>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2223 | |
Brian Curtin | 52173d4 | 2010-12-02 18:29:18 +0000 | [diff] [blame] | 2224 | .. note:: |
| 2225 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2226 | On Windows, the *SeCreateSymbolicLinkPrivilege* is required in order to |
| 2227 | successfully create symlinks. This privilege is not typically granted to |
| 2228 | regular users but is available to accounts which can escalate privileges |
| 2229 | to the administrator level. Either obtaining the privilege or running your |
Brian Curtin | 9624559 | 2010-12-28 17:08:22 +0000 | [diff] [blame] | 2230 | application as an administrator are ways to successfully create symlinks. |
| 2231 | |
Jason R. Coombs | 3a09286 | 2013-05-27 23:21:28 -0400 | [diff] [blame] | 2232 | |
Brian Curtin | 9624559 | 2010-12-28 17:08:22 +0000 | [diff] [blame] | 2233 | :exc:`OSError` is raised when the function is called by an unprivileged |
| 2234 | user. |
Brian Curtin | d40e6f7 | 2010-07-08 21:39:08 +0000 | [diff] [blame] | 2235 | |
Georg Brandl | 64a41ed | 2010-10-06 08:52:48 +0000 | [diff] [blame] | 2236 | Availability: Unix, Windows. |
Brian Curtin | c739569 | 2010-07-09 15:15:09 +0000 | [diff] [blame] | 2237 | |
Georg Brandl | b382337 | 2010-07-10 08:58:37 +0000 | [diff] [blame] | 2238 | .. versionchanged:: 3.2 |
| 2239 | Added support for Windows 6.0 (Vista) symbolic links. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2240 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2241 | .. versionadded:: 3.3 |
| 2242 | Added the *dir_fd* argument, and now allow *target_is_directory* |
| 2243 | on non-Windows platforms. |
| 2244 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2245 | |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 2246 | .. function:: sync() |
| 2247 | |
| 2248 | Force write of everything to disk. |
| 2249 | |
| 2250 | Availability: Unix. |
| 2251 | |
| 2252 | .. versionadded:: 3.3 |
| 2253 | |
| 2254 | |
| 2255 | .. function:: truncate(path, length) |
| 2256 | |
| 2257 | Truncate the file corresponding to *path*, so that it is at most |
| 2258 | *length* bytes in size. |
| 2259 | |
Georg Brandl | 306336b | 2012-06-24 12:55:33 +0200 | [diff] [blame] | 2260 | This function can support :ref:`specifying a file descriptor <path_fd>`. |
| 2261 | |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 2262 | Availability: Unix. |
| 2263 | |
| 2264 | .. versionadded:: 3.3 |
| 2265 | |
| 2266 | |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 2267 | .. function:: unlink(path, *, dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2268 | |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 2269 | Remove (delete) the file *path*. This function is identical to |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 2270 | :func:`remove`; the ``unlink`` name is its traditional Unix |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2271 | name. Please see the documentation for :func:`remove` for |
| 2272 | further information. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2273 | |
| 2274 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2275 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2276 | .. versionadded:: 3.3 |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 2277 | The *dir_fd* parameter. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2278 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2279 | |
Martin Panter | bf19d16 | 2015-09-09 01:01:13 +0000 | [diff] [blame] | 2280 | .. function:: utime(path, times=None, *[, ns], dir_fd=None, follow_symlinks=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2281 | |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2282 | Set the access and modified times of the file specified by *path*. |
| 2283 | |
| 2284 | :func:`utime` takes two optional parameters, *times* and *ns*. |
| 2285 | These specify the times set on *path* and are used as follows: |
| 2286 | |
Martin Panter | bf19d16 | 2015-09-09 01:01:13 +0000 | [diff] [blame] | 2287 | - If *ns* is specified, |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2288 | it must be a 2-tuple of the form ``(atime_ns, mtime_ns)`` |
| 2289 | where each member is an int expressing nanoseconds. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2290 | - If *times* is not ``None``, |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2291 | it must be a 2-tuple of the form ``(atime, mtime)`` |
| 2292 | where each member is an int or float expressing seconds. |
Martin Panter | bf19d16 | 2015-09-09 01:01:13 +0000 | [diff] [blame] | 2293 | - If *times* is ``None`` and *ns* is unspecified, |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2294 | this is equivalent to specifying ``ns=(atime_ns, mtime_ns)`` |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2295 | where both times are the current time. |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2296 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2297 | It is an error to specify tuples for both *times* and *ns*. |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2298 | |
| 2299 | Whether a directory can be given for *path* |
Brian Curtin | 52fbea1 | 2011-11-06 13:41:17 -0600 | [diff] [blame] | 2300 | depends on whether the operating system implements directories as files |
| 2301 | (for example, Windows does not). Note that the exact times you set here may |
| 2302 | not be returned by a subsequent :func:`~os.stat` call, depending on the |
| 2303 | resolution with which your operating system records access and modification |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2304 | times; see :func:`~os.stat`. The best way to preserve exact times is to |
| 2305 | use the *st_atime_ns* and *st_mtime_ns* fields from the :func:`os.stat` |
| 2306 | result object with the *ns* parameter to `utime`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2307 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 2308 | This function can support :ref:`specifying a file descriptor <path_fd>`, |
| 2309 | :ref:`paths relative to directory descriptors <dir_fd>` and :ref:`not |
| 2310 | following symlinks <follow_symlinks>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2311 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2312 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2313 | |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2314 | .. versionadded:: 3.3 |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2315 | Added support for specifying an open file descriptor for *path*, |
| 2316 | and the *dir_fd*, *follow_symlinks*, and *ns* parameters. |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2317 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2318 | |
Georg Brandl | 1824415 | 2009-09-02 20:34:52 +0000 | [diff] [blame] | 2319 | .. function:: walk(top, topdown=True, onerror=None, followlinks=False) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2320 | |
| 2321 | .. index:: |
| 2322 | single: directory; walking |
| 2323 | single: directory; traversal |
| 2324 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2325 | Generate the file names in a directory tree by walking the tree |
| 2326 | either top-down or bottom-up. For each directory in the tree rooted at directory |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2327 | *top* (including *top* itself), it yields a 3-tuple ``(dirpath, dirnames, |
| 2328 | filenames)``. |
| 2329 | |
| 2330 | *dirpath* is a string, the path to the directory. *dirnames* is a list of the |
| 2331 | names of the subdirectories in *dirpath* (excluding ``'.'`` and ``'..'``). |
| 2332 | *filenames* is a list of the names of the non-directory files in *dirpath*. |
| 2333 | Note that the names in the lists contain no path components. To get a full path |
| 2334 | (which begins with *top*) to a file or directory in *dirpath*, do |
| 2335 | ``os.path.join(dirpath, name)``. |
| 2336 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2337 | If optional argument *topdown* is ``True`` or not specified, the triple for a |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2338 | directory is generated before the triples for any of its subdirectories |
Benjamin Peterson | e58e0c7 | 2014-06-15 20:51:12 -0700 | [diff] [blame] | 2339 | (directories are generated top-down). If *topdown* is ``False``, the triple |
| 2340 | for a directory is generated after the triples for all of its subdirectories |
| 2341 | (directories are generated bottom-up). No matter the value of *topdown*, the |
| 2342 | list of subdirectories is retrieved before the tuples for the directory and |
| 2343 | its subdirectories are generated. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2344 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2345 | When *topdown* is ``True``, the caller can modify the *dirnames* list in-place |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2346 | (perhaps using :keyword:`del` or slice assignment), and :func:`walk` will only |
| 2347 | recurse into the subdirectories whose names remain in *dirnames*; this can be |
| 2348 | used to prune the search, impose a specific order of visiting, or even to inform |
| 2349 | :func:`walk` about directories the caller creates or renames before it resumes |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2350 | :func:`walk` again. Modifying *dirnames* when *topdown* is ``False`` is |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2351 | ineffective, because in bottom-up mode the directories in *dirnames* are |
| 2352 | generated before *dirpath* itself is generated. |
| 2353 | |
Ezio Melotti | 67494f2 | 2011-10-18 12:59:39 +0300 | [diff] [blame] | 2354 | By default, errors from the :func:`listdir` call are ignored. If optional |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2355 | argument *onerror* is specified, it should be a function; it will be called with |
| 2356 | one argument, an :exc:`OSError` instance. It can report the error to continue |
| 2357 | with the walk, or raise the exception to abort the walk. Note that the filename |
| 2358 | is available as the ``filename`` attribute of the exception object. |
| 2359 | |
| 2360 | By default, :func:`walk` will not walk down into symbolic links that resolve to |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2361 | directories. Set *followlinks* to ``True`` to visit directories pointed to by |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2362 | symlinks, on systems that support them. |
| 2363 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2364 | .. note:: |
| 2365 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 2366 | Be aware that setting *followlinks* to ``True`` can lead to infinite |
| 2367 | recursion if a link points to a parent directory of itself. :func:`walk` |
| 2368 | does not keep track of the directories it visited already. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2369 | |
| 2370 | .. note:: |
| 2371 | |
| 2372 | If you pass a relative pathname, don't change the current working directory |
| 2373 | between resumptions of :func:`walk`. :func:`walk` never changes the current |
| 2374 | directory, and assumes that its caller doesn't either. |
| 2375 | |
| 2376 | This example displays the number of bytes taken by non-directory files in each |
| 2377 | directory under the starting directory, except that it doesn't look under any |
| 2378 | CVS subdirectory:: |
| 2379 | |
| 2380 | import os |
| 2381 | from os.path import join, getsize |
| 2382 | for root, dirs, files in os.walk('python/Lib/email'): |
Georg Brandl | 6911e3c | 2007-09-04 07:15:32 +0000 | [diff] [blame] | 2383 | print(root, "consumes", end=" ") |
| 2384 | print(sum(getsize(join(root, name)) for name in files), end=" ") |
| 2385 | print("bytes in", len(files), "non-directory files") |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2386 | if 'CVS' in dirs: |
| 2387 | dirs.remove('CVS') # don't visit CVS directories |
| 2388 | |
Victor Stinner | 47c41b4 | 2015-03-10 13:31:47 +0100 | [diff] [blame] | 2389 | In the next example (simple implementation of :func:`shutil.rmtree`), |
| 2390 | walking the tree bottom-up is essential, :func:`rmdir` doesn't allow |
| 2391 | deleting a directory before the directory is empty:: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2392 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2393 | # Delete everything reachable from the directory named in "top", |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2394 | # assuming there are no symbolic links. |
| 2395 | # CAUTION: This is dangerous! For example, if top == '/', it |
| 2396 | # could delete all your disk files. |
| 2397 | import os |
| 2398 | for root, dirs, files in os.walk(top, topdown=False): |
| 2399 | for name in files: |
| 2400 | os.remove(os.path.join(root, name)) |
| 2401 | for name in dirs: |
| 2402 | os.rmdir(os.path.join(root, name)) |
| 2403 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2404 | |
Larry Hastings | b403806 | 2012-07-15 10:57:38 -0700 | [diff] [blame] | 2405 | .. function:: fwalk(top='.', topdown=True, onerror=None, *, follow_symlinks=False, dir_fd=None) |
Charles-François Natali | 7372b06 | 2012-02-05 15:15:38 +0100 | [diff] [blame] | 2406 | |
| 2407 | .. index:: |
| 2408 | single: directory; walking |
| 2409 | single: directory; traversal |
| 2410 | |
Eli Bendersky | d049d5c | 2012-02-11 09:52:29 +0200 | [diff] [blame] | 2411 | This behaves exactly like :func:`walk`, except that it yields a 4-tuple |
Larry Hastings | c48fe98 | 2012-06-25 04:49:05 -0700 | [diff] [blame] | 2412 | ``(dirpath, dirnames, filenames, dirfd)``, and it supports ``dir_fd``. |
Charles-François Natali | 7372b06 | 2012-02-05 15:15:38 +0100 | [diff] [blame] | 2413 | |
| 2414 | *dirpath*, *dirnames* and *filenames* are identical to :func:`walk` output, |
| 2415 | and *dirfd* is a file descriptor referring to the directory *dirpath*. |
| 2416 | |
Larry Hastings | c48fe98 | 2012-06-25 04:49:05 -0700 | [diff] [blame] | 2417 | This function always supports :ref:`paths relative to directory descriptors |
Larry Hastings | b403806 | 2012-07-15 10:57:38 -0700 | [diff] [blame] | 2418 | <dir_fd>` and :ref:`not following symlinks <follow_symlinks>`. Note however |
Larry Hastings | 950b76a | 2012-07-15 17:32:36 -0700 | [diff] [blame] | 2419 | that, unlike other functions, the :func:`fwalk` default value for |
Larry Hastings | b403806 | 2012-07-15 10:57:38 -0700 | [diff] [blame] | 2420 | *follow_symlinks* is ``False``. |
Larry Hastings | c48fe98 | 2012-06-25 04:49:05 -0700 | [diff] [blame] | 2421 | |
Charles-François Natali | 7372b06 | 2012-02-05 15:15:38 +0100 | [diff] [blame] | 2422 | .. note:: |
| 2423 | |
| 2424 | Since :func:`fwalk` yields file descriptors, those are only valid until |
| 2425 | the next iteration step, so you should duplicate them (e.g. with |
| 2426 | :func:`dup`) if you want to keep them longer. |
| 2427 | |
| 2428 | This example displays the number of bytes taken by non-directory files in each |
| 2429 | directory under the starting directory, except that it doesn't look under any |
| 2430 | CVS subdirectory:: |
| 2431 | |
| 2432 | import os |
| 2433 | for root, dirs, files, rootfd in os.fwalk('python/Lib/email'): |
| 2434 | print(root, "consumes", end="") |
Hynek Schlawack | 1729b8f | 2012-06-24 16:11:08 +0200 | [diff] [blame] | 2435 | print(sum([os.stat(name, dir_fd=rootfd).st_size for name in files]), |
Charles-François Natali | 7372b06 | 2012-02-05 15:15:38 +0100 | [diff] [blame] | 2436 | end="") |
| 2437 | print("bytes in", len(files), "non-directory files") |
| 2438 | if 'CVS' in dirs: |
| 2439 | dirs.remove('CVS') # don't visit CVS directories |
| 2440 | |
| 2441 | In the next example, walking the tree bottom-up is essential: |
Victor Stinner | 69a6ca5 | 2012-08-05 15:18:02 +0200 | [diff] [blame] | 2442 | :func:`rmdir` doesn't allow deleting a directory before the directory is |
Charles-François Natali | 7372b06 | 2012-02-05 15:15:38 +0100 | [diff] [blame] | 2443 | empty:: |
| 2444 | |
| 2445 | # Delete everything reachable from the directory named in "top", |
| 2446 | # assuming there are no symbolic links. |
| 2447 | # CAUTION: This is dangerous! For example, if top == '/', it |
| 2448 | # could delete all your disk files. |
| 2449 | import os |
| 2450 | for root, dirs, files, rootfd in os.fwalk(top, topdown=False): |
| 2451 | for name in files: |
Victor Stinner | 69a6ca5 | 2012-08-05 15:18:02 +0200 | [diff] [blame] | 2452 | os.unlink(name, dir_fd=rootfd) |
Charles-François Natali | 7372b06 | 2012-02-05 15:15:38 +0100 | [diff] [blame] | 2453 | for name in dirs: |
Victor Stinner | 69a6ca5 | 2012-08-05 15:18:02 +0200 | [diff] [blame] | 2454 | os.rmdir(name, dir_fd=rootfd) |
Charles-François Natali | 7372b06 | 2012-02-05 15:15:38 +0100 | [diff] [blame] | 2455 | |
| 2456 | Availability: Unix. |
| 2457 | |
| 2458 | .. versionadded:: 3.3 |
| 2459 | |
| 2460 | |
Georg Brandl | b9831ab | 2012-06-24 11:57:07 +0200 | [diff] [blame] | 2461 | Linux extended attributes |
| 2462 | ~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 2463 | |
| 2464 | .. versionadded:: 3.3 |
| 2465 | |
| 2466 | These functions are all available on Linux only. |
| 2467 | |
| 2468 | .. function:: getxattr(path, attribute, *, follow_symlinks=True) |
| 2469 | |
| 2470 | Return the value of the extended filesystem attribute *attribute* for |
| 2471 | *path*. *attribute* can be bytes or str. If it is str, it is encoded |
| 2472 | with the filesystem encoding. |
| 2473 | |
| 2474 | This function can support :ref:`specifying a file descriptor <path_fd>` and |
| 2475 | :ref:`not following symlinks <follow_symlinks>`. |
| 2476 | |
| 2477 | |
| 2478 | .. function:: listxattr(path=None, *, follow_symlinks=True) |
| 2479 | |
| 2480 | Return a list of the extended filesystem attributes on *path*. The |
| 2481 | attributes in the list are represented as strings decoded with the filesystem |
| 2482 | encoding. If *path* is ``None``, :func:`listxattr` will examine the current |
| 2483 | directory. |
| 2484 | |
| 2485 | This function can support :ref:`specifying a file descriptor <path_fd>` and |
| 2486 | :ref:`not following symlinks <follow_symlinks>`. |
| 2487 | |
| 2488 | |
| 2489 | .. function:: removexattr(path, attribute, *, follow_symlinks=True) |
| 2490 | |
| 2491 | Removes the extended filesystem attribute *attribute* from *path*. |
| 2492 | *attribute* should be bytes or str. If it is a string, it is encoded |
| 2493 | with the filesystem encoding. |
| 2494 | |
| 2495 | This function can support :ref:`specifying a file descriptor <path_fd>` and |
| 2496 | :ref:`not following symlinks <follow_symlinks>`. |
| 2497 | |
| 2498 | |
| 2499 | .. function:: setxattr(path, attribute, value, flags=0, *, follow_symlinks=True) |
| 2500 | |
| 2501 | Set the extended filesystem attribute *attribute* on *path* to *value*. |
| 2502 | *attribute* must be a bytes or str with no embedded NULs. If it is a str, |
| 2503 | it is encoded with the filesystem encoding. *flags* may be |
| 2504 | :data:`XATTR_REPLACE` or :data:`XATTR_CREATE`. If :data:`XATTR_REPLACE` is |
| 2505 | given and the attribute does not exist, ``EEXISTS`` will be raised. |
| 2506 | If :data:`XATTR_CREATE` is given and the attribute already exists, the |
| 2507 | attribute will not be created and ``ENODATA`` will be raised. |
| 2508 | |
| 2509 | This function can support :ref:`specifying a file descriptor <path_fd>` and |
| 2510 | :ref:`not following symlinks <follow_symlinks>`. |
| 2511 | |
| 2512 | .. note:: |
| 2513 | |
| 2514 | A bug in Linux kernel versions less than 2.6.39 caused the flags argument |
| 2515 | to be ignored on some filesystems. |
| 2516 | |
| 2517 | |
| 2518 | .. data:: XATTR_SIZE_MAX |
| 2519 | |
| 2520 | The maximum size the value of an extended attribute can be. Currently, this |
Serhiy Storchaka | f8def28 | 2013-02-16 17:29:56 +0200 | [diff] [blame] | 2521 | is 64 KiB on Linux. |
Georg Brandl | b9831ab | 2012-06-24 11:57:07 +0200 | [diff] [blame] | 2522 | |
| 2523 | |
| 2524 | .. data:: XATTR_CREATE |
| 2525 | |
| 2526 | This is a possible value for the flags argument in :func:`setxattr`. It |
| 2527 | indicates the operation must create an attribute. |
| 2528 | |
| 2529 | |
| 2530 | .. data:: XATTR_REPLACE |
| 2531 | |
| 2532 | This is a possible value for the flags argument in :func:`setxattr`. It |
| 2533 | indicates the operation must replace an existing attribute. |
| 2534 | |
| 2535 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2536 | .. _os-process: |
| 2537 | |
| 2538 | Process Management |
| 2539 | ------------------ |
| 2540 | |
| 2541 | These functions may be used to create and manage processes. |
| 2542 | |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 2543 | The various :func:`exec\* <execl>` functions take a list of arguments for the new |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2544 | program loaded into the process. In each case, the first of these arguments is |
| 2545 | passed to the new program as its own name rather than as an argument a user may |
| 2546 | have typed on a command line. For the C programmer, this is the ``argv[0]`` |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 2547 | passed to a program's :c:func:`main`. For example, ``os.execv('/bin/echo', |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2548 | ['foo', 'bar'])`` will only print ``bar`` on standard output; ``foo`` will seem |
| 2549 | to be ignored. |
| 2550 | |
| 2551 | |
| 2552 | .. function:: abort() |
| 2553 | |
| 2554 | Generate a :const:`SIGABRT` signal to the current process. On Unix, the default |
| 2555 | behavior is to produce a core dump; on Windows, the process immediately returns |
Victor Stinner | 6e2e3b9 | 2011-07-08 02:26:39 +0200 | [diff] [blame] | 2556 | an exit code of ``3``. Be aware that calling this function will not call the |
| 2557 | Python signal handler registered for :const:`SIGABRT` with |
| 2558 | :func:`signal.signal`. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2559 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2560 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2561 | |
| 2562 | |
| 2563 | .. function:: execl(path, arg0, arg1, ...) |
| 2564 | execle(path, arg0, arg1, ..., env) |
| 2565 | execlp(file, arg0, arg1, ...) |
| 2566 | execlpe(file, arg0, arg1, ..., env) |
| 2567 | execv(path, args) |
| 2568 | execve(path, args, env) |
| 2569 | execvp(file, args) |
| 2570 | execvpe(file, args, env) |
| 2571 | |
| 2572 | These functions all execute a new program, replacing the current process; they |
| 2573 | do not return. On Unix, the new executable is loaded into the current process, |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2574 | and will have the same process id as the caller. Errors will be reported as |
Georg Brandl | 48310cd | 2009-01-03 21:18:54 +0000 | [diff] [blame] | 2575 | :exc:`OSError` exceptions. |
Benjamin Peterson | e9bbc8b | 2008-09-28 02:06:32 +0000 | [diff] [blame] | 2576 | |
| 2577 | The current process is replaced immediately. Open file objects and |
| 2578 | descriptors are not flushed, so if there may be data buffered |
| 2579 | on these open files, you should flush them using |
| 2580 | :func:`sys.stdout.flush` or :func:`os.fsync` before calling an |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 2581 | :func:`exec\* <execl>` function. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2582 | |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 2583 | The "l" and "v" variants of the :func:`exec\* <execl>` functions differ in how |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2584 | command-line arguments are passed. The "l" variants are perhaps the easiest |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2585 | to work with if the number of parameters is fixed when the code is written; the |
| 2586 | individual parameters simply become additional parameters to the :func:`execl\*` |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2587 | functions. The "v" variants are good when the number of parameters is |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2588 | variable, with the arguments being passed in a list or tuple as the *args* |
| 2589 | parameter. In either case, the arguments to the child process should start with |
| 2590 | the name of the command being run, but this is not enforced. |
| 2591 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2592 | The variants which include a "p" near the end (:func:`execlp`, |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2593 | :func:`execlpe`, :func:`execvp`, and :func:`execvpe`) will use the |
| 2594 | :envvar:`PATH` environment variable to locate the program *file*. When the |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 2595 | environment is being replaced (using one of the :func:`exec\*e <execl>` variants, |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2596 | discussed in the next paragraph), the new environment is used as the source of |
| 2597 | the :envvar:`PATH` variable. The other variants, :func:`execl`, :func:`execle`, |
| 2598 | :func:`execv`, and :func:`execve`, will not use the :envvar:`PATH` variable to |
| 2599 | locate the executable; *path* must contain an appropriate absolute or relative |
| 2600 | path. |
| 2601 | |
| 2602 | For :func:`execle`, :func:`execlpe`, :func:`execve`, and :func:`execvpe` (note |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2603 | that these all end in "e"), the *env* parameter must be a mapping which is |
Christian Heimes | a342c01 | 2008-04-20 21:01:16 +0000 | [diff] [blame] | 2604 | used to define the environment variables for the new process (these are used |
| 2605 | instead of the current process' environment); the functions :func:`execl`, |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2606 | :func:`execlp`, :func:`execv`, and :func:`execvp` all cause the new process to |
Georg Brandl | 48310cd | 2009-01-03 21:18:54 +0000 | [diff] [blame] | 2607 | inherit the environment of the current process. |
Benjamin Peterson | e9bbc8b | 2008-09-28 02:06:32 +0000 | [diff] [blame] | 2608 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2609 | For :func:`execve` on some platforms, *path* may also be specified as an open |
| 2610 | file descriptor. This functionality may not be supported on your platform; |
| 2611 | you can check whether or not it is available using :data:`os.supports_fd`. |
| 2612 | If it is unavailable, using it will raise a :exc:`NotImplementedError`. |
| 2613 | |
Benjamin Peterson | e9bbc8b | 2008-09-28 02:06:32 +0000 | [diff] [blame] | 2614 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2615 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2616 | .. versionadded:: 3.3 |
| 2617 | Added support for specifying an open file descriptor for *path* |
| 2618 | for :func:`execve`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2619 | |
| 2620 | .. function:: _exit(n) |
| 2621 | |
Georg Brandl | 6f4e68d | 2010-10-17 10:51:45 +0000 | [diff] [blame] | 2622 | Exit the process with status *n*, without calling cleanup handlers, flushing |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2623 | stdio buffers, etc. |
| 2624 | |
| 2625 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2626 | |
| 2627 | .. note:: |
| 2628 | |
Georg Brandl | 6f4e68d | 2010-10-17 10:51:45 +0000 | [diff] [blame] | 2629 | The standard way to exit is ``sys.exit(n)``. :func:`_exit` should |
| 2630 | normally only be used in the child process after a :func:`fork`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2631 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2632 | The following exit codes are defined and can be used with :func:`_exit`, |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2633 | although they are not required. These are typically used for system programs |
| 2634 | written in Python, such as a mail server's external command delivery program. |
| 2635 | |
| 2636 | .. note:: |
| 2637 | |
| 2638 | Some of these may not be available on all Unix platforms, since there is some |
| 2639 | variation. These constants are defined where they are defined by the underlying |
| 2640 | platform. |
| 2641 | |
| 2642 | |
| 2643 | .. data:: EX_OK |
| 2644 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2645 | Exit code that means no error occurred. |
| 2646 | |
| 2647 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2648 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2649 | |
| 2650 | .. data:: EX_USAGE |
| 2651 | |
| 2652 | Exit code that means the command was used incorrectly, such as when the wrong |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2653 | number of arguments are given. |
| 2654 | |
| 2655 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2656 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2657 | |
| 2658 | .. data:: EX_DATAERR |
| 2659 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2660 | Exit code that means the input data was incorrect. |
| 2661 | |
| 2662 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2663 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2664 | |
| 2665 | .. data:: EX_NOINPUT |
| 2666 | |
| 2667 | Exit code that means an input file did not exist or was not readable. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2668 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2669 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2670 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2671 | |
| 2672 | .. data:: EX_NOUSER |
| 2673 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2674 | Exit code that means a specified user did not exist. |
| 2675 | |
| 2676 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2677 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2678 | |
| 2679 | .. data:: EX_NOHOST |
| 2680 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2681 | Exit code that means a specified host did not exist. |
| 2682 | |
| 2683 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2684 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2685 | |
| 2686 | .. data:: EX_UNAVAILABLE |
| 2687 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2688 | Exit code that means that a required service is unavailable. |
| 2689 | |
| 2690 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2691 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2692 | |
| 2693 | .. data:: EX_SOFTWARE |
| 2694 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2695 | Exit code that means an internal software error was detected. |
| 2696 | |
| 2697 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2698 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2699 | |
| 2700 | .. data:: EX_OSERR |
| 2701 | |
| 2702 | Exit code that means an operating system error was detected, such as the |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2703 | inability to fork or create a pipe. |
| 2704 | |
| 2705 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2706 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2707 | |
| 2708 | .. data:: EX_OSFILE |
| 2709 | |
| 2710 | Exit code that means some system file did not exist, could not be opened, or had |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2711 | some other kind of error. |
| 2712 | |
| 2713 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2714 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2715 | |
| 2716 | .. data:: EX_CANTCREAT |
| 2717 | |
| 2718 | Exit code that means a user specified output file could not be created. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2719 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2720 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2721 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2722 | |
| 2723 | .. data:: EX_IOERR |
| 2724 | |
| 2725 | Exit code that means that an error occurred while doing I/O on some file. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2726 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2727 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2728 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2729 | |
| 2730 | .. data:: EX_TEMPFAIL |
| 2731 | |
| 2732 | Exit code that means a temporary failure occurred. This indicates something |
| 2733 | that may not really be an error, such as a network connection that couldn't be |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2734 | made during a retryable operation. |
| 2735 | |
| 2736 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2737 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2738 | |
| 2739 | .. data:: EX_PROTOCOL |
| 2740 | |
| 2741 | Exit code that means that a protocol exchange was illegal, invalid, or not |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2742 | understood. |
| 2743 | |
| 2744 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2745 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2746 | |
| 2747 | .. data:: EX_NOPERM |
| 2748 | |
| 2749 | Exit code that means that there were insufficient permissions to perform the |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2750 | operation (but not intended for file system problems). |
| 2751 | |
| 2752 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2753 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2754 | |
| 2755 | .. data:: EX_CONFIG |
| 2756 | |
| 2757 | Exit code that means that some kind of configuration error occurred. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2758 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2759 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2760 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2761 | |
| 2762 | .. data:: EX_NOTFOUND |
| 2763 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2764 | Exit code that means something like "an entry was not found". |
| 2765 | |
| 2766 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2767 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2768 | |
| 2769 | .. function:: fork() |
| 2770 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2771 | Fork a child process. Return ``0`` in the child and the child's process id in the |
Christian Heimes | dd15f6c | 2008-03-16 00:07:10 +0000 | [diff] [blame] | 2772 | parent. If an error occurs :exc:`OSError` is raised. |
Benjamin Peterson | bcd8ac3 | 2008-10-10 22:20:52 +0000 | [diff] [blame] | 2773 | |
Larry Hastings | 3732ed2 | 2014-03-15 21:13:56 -0700 | [diff] [blame] | 2774 | Note that some platforms including FreeBSD <= 6.3 and Cygwin have |
Benjamin Peterson | bcd8ac3 | 2008-10-10 22:20:52 +0000 | [diff] [blame] | 2775 | known issues when using fork() from a thread. |
| 2776 | |
Christian Heimes | 3046fe4 | 2013-10-29 21:08:56 +0100 | [diff] [blame] | 2777 | .. warning:: |
| 2778 | |
| 2779 | See :mod:`ssl` for applications that use the SSL module with fork(). |
| 2780 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2781 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2782 | |
| 2783 | |
| 2784 | .. function:: forkpty() |
| 2785 | |
| 2786 | Fork a child process, using a new pseudo-terminal as the child's controlling |
| 2787 | terminal. Return a pair of ``(pid, fd)``, where *pid* is ``0`` in the child, the |
| 2788 | new child's process id in the parent, and *fd* is the file descriptor of the |
| 2789 | master end of the pseudo-terminal. For a more portable approach, use the |
Christian Heimes | dd15f6c | 2008-03-16 00:07:10 +0000 | [diff] [blame] | 2790 | :mod:`pty` module. If an error occurs :exc:`OSError` is raised. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2791 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2792 | Availability: some flavors of Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2793 | |
| 2794 | |
| 2795 | .. function:: kill(pid, sig) |
| 2796 | |
| 2797 | .. index:: |
| 2798 | single: process; killing |
| 2799 | single: process; signalling |
| 2800 | |
| 2801 | Send signal *sig* to the process *pid*. Constants for the specific signals |
| 2802 | available on the host platform are defined in the :mod:`signal` module. |
Brian Curtin | eb24d74 | 2010-04-12 17:16:38 +0000 | [diff] [blame] | 2803 | |
| 2804 | Windows: The :data:`signal.CTRL_C_EVENT` and |
| 2805 | :data:`signal.CTRL_BREAK_EVENT` signals are special signals which can |
| 2806 | only be sent to console processes which share a common console window, |
| 2807 | e.g., some subprocesses. Any other value for *sig* will cause the process |
| 2808 | to be unconditionally killed by the TerminateProcess API, and the exit code |
| 2809 | will be set to *sig*. The Windows version of :func:`kill` additionally takes |
| 2810 | process handles to be killed. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2811 | |
Victor Stinner | b3e7219 | 2011-05-08 01:46:11 +0200 | [diff] [blame] | 2812 | See also :func:`signal.pthread_kill`. |
| 2813 | |
Georg Brandl | 67b21b7 | 2010-08-17 15:07:14 +0000 | [diff] [blame] | 2814 | .. versionadded:: 3.2 |
| 2815 | Windows support. |
Brian Curtin | 904bd39 | 2010-04-20 15:28:06 +0000 | [diff] [blame] | 2816 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2817 | |
| 2818 | .. function:: killpg(pgid, sig) |
| 2819 | |
| 2820 | .. index:: |
| 2821 | single: process; killing |
| 2822 | single: process; signalling |
| 2823 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2824 | Send the signal *sig* to the process group *pgid*. |
| 2825 | |
| 2826 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2827 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2828 | |
| 2829 | .. function:: nice(increment) |
| 2830 | |
| 2831 | Add *increment* to the process's "niceness". Return the new niceness. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2832 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2833 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2834 | |
| 2835 | |
| 2836 | .. function:: plock(op) |
| 2837 | |
| 2838 | Lock program segments into memory. The value of *op* (defined in |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2839 | ``<sys/lock.h>``) determines which segments are locked. |
| 2840 | |
| 2841 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2842 | |
| 2843 | |
Martin Panter | bf19d16 | 2015-09-09 01:01:13 +0000 | [diff] [blame] | 2844 | .. function:: popen(cmd, mode='r', buffering=-1) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2845 | |
Martin Panter | bf19d16 | 2015-09-09 01:01:13 +0000 | [diff] [blame] | 2846 | Open a pipe to or from command *cmd*. |
| 2847 | The return value is an open file object |
Victor Stinner | 992019c | 2014-07-24 12:42:45 +0200 | [diff] [blame] | 2848 | connected to the pipe, which can be read or written depending on whether *mode* |
| 2849 | is ``'r'`` (default) or ``'w'``. The *buffering* argument has the same meaning as |
| 2850 | the corresponding argument to the built-in :func:`open` function. The |
| 2851 | returned file object reads or writes text strings rather than bytes. |
| 2852 | |
| 2853 | The ``close`` method returns :const:`None` if the subprocess exited |
| 2854 | successfully, or the subprocess's return code if there was an |
| 2855 | error. On POSIX systems, if the return code is positive it |
| 2856 | represents the return value of the process left-shifted by one |
| 2857 | byte. If the return code is negative, the process was terminated |
| 2858 | by the signal given by the negated value of the return code. (For |
| 2859 | example, the return value might be ``- signal.SIGKILL`` if the |
| 2860 | subprocess was killed.) On Windows systems, the return value |
| 2861 | contains the signed integer return code from the child process. |
| 2862 | |
| 2863 | This is implemented using :class:`subprocess.Popen`; see that class's |
| 2864 | documentation for more powerful ways to manage and communicate with |
| 2865 | subprocesses. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2866 | |
| 2867 | |
| 2868 | .. function:: spawnl(mode, path, ...) |
| 2869 | spawnle(mode, path, ..., env) |
| 2870 | spawnlp(mode, file, ...) |
| 2871 | spawnlpe(mode, file, ..., env) |
| 2872 | spawnv(mode, path, args) |
| 2873 | spawnve(mode, path, args, env) |
| 2874 | spawnvp(mode, file, args) |
| 2875 | spawnvpe(mode, file, args, env) |
| 2876 | |
| 2877 | Execute the program *path* in a new process. |
| 2878 | |
| 2879 | (Note that the :mod:`subprocess` module provides more powerful facilities for |
| 2880 | spawning new processes and retrieving their results; using that module is |
Benjamin Peterson | 87c8d87 | 2009-06-11 22:54:11 +0000 | [diff] [blame] | 2881 | preferable to using these functions. Check especially the |
| 2882 | :ref:`subprocess-replacements` section.) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2883 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2884 | If *mode* is :const:`P_NOWAIT`, this function returns the process id of the new |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2885 | process; if *mode* is :const:`P_WAIT`, returns the process's exit code if it |
| 2886 | exits normally, or ``-signal``, where *signal* is the signal that killed the |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2887 | process. On Windows, the process id will actually be the process handle, so can |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2888 | be used with the :func:`waitpid` function. |
| 2889 | |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 2890 | The "l" and "v" variants of the :func:`spawn\* <spawnl>` functions differ in how |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2891 | command-line arguments are passed. The "l" variants are perhaps the easiest |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2892 | to work with if the number of parameters is fixed when the code is written; the |
| 2893 | individual parameters simply become additional parameters to the |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2894 | :func:`spawnl\*` functions. The "v" variants are good when the number of |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2895 | parameters is variable, with the arguments being passed in a list or tuple as |
| 2896 | the *args* parameter. In either case, the arguments to the child process must |
| 2897 | start with the name of the command being run. |
| 2898 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2899 | The variants which include a second "p" near the end (:func:`spawnlp`, |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2900 | :func:`spawnlpe`, :func:`spawnvp`, and :func:`spawnvpe`) will use the |
| 2901 | :envvar:`PATH` environment variable to locate the program *file*. When the |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 2902 | environment is being replaced (using one of the :func:`spawn\*e <spawnl>` variants, |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2903 | discussed in the next paragraph), the new environment is used as the source of |
| 2904 | the :envvar:`PATH` variable. The other variants, :func:`spawnl`, |
| 2905 | :func:`spawnle`, :func:`spawnv`, and :func:`spawnve`, will not use the |
| 2906 | :envvar:`PATH` variable to locate the executable; *path* must contain an |
| 2907 | appropriate absolute or relative path. |
| 2908 | |
| 2909 | For :func:`spawnle`, :func:`spawnlpe`, :func:`spawnve`, and :func:`spawnvpe` |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2910 | (note that these all end in "e"), the *env* parameter must be a mapping |
Christian Heimes | a342c01 | 2008-04-20 21:01:16 +0000 | [diff] [blame] | 2911 | which is used to define the environment variables for the new process (they are |
| 2912 | used instead of the current process' environment); the functions |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2913 | :func:`spawnl`, :func:`spawnlp`, :func:`spawnv`, and :func:`spawnvp` all cause |
Benjamin Peterson | d23f822 | 2009-04-05 19:13:16 +0000 | [diff] [blame] | 2914 | the new process to inherit the environment of the current process. Note that |
| 2915 | keys and values in the *env* dictionary must be strings; invalid keys or |
| 2916 | values will cause the function to fail, with a return value of ``127``. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2917 | |
| 2918 | As an example, the following calls to :func:`spawnlp` and :func:`spawnvpe` are |
| 2919 | equivalent:: |
| 2920 | |
| 2921 | import os |
| 2922 | os.spawnlp(os.P_WAIT, 'cp', 'cp', 'index.html', '/dev/null') |
| 2923 | |
| 2924 | L = ['cp', 'index.html', '/dev/null'] |
| 2925 | os.spawnvpe(os.P_WAIT, 'cp', L, os.environ) |
| 2926 | |
| 2927 | Availability: Unix, Windows. :func:`spawnlp`, :func:`spawnlpe`, :func:`spawnvp` |
Antoine Pitrou | 0e752dd | 2011-07-19 01:26:58 +0200 | [diff] [blame] | 2928 | and :func:`spawnvpe` are not available on Windows. :func:`spawnle` and |
| 2929 | :func:`spawnve` are not thread-safe on Windows; we advise you to use the |
| 2930 | :mod:`subprocess` module instead. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2931 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2932 | |
| 2933 | .. data:: P_NOWAIT |
| 2934 | P_NOWAITO |
| 2935 | |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 2936 | Possible values for the *mode* parameter to the :func:`spawn\* <spawnl>` family of |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2937 | functions. If either of these values is given, the :func:`spawn\*` functions |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2938 | will return as soon as the new process has been created, with the process id as |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2939 | the return value. |
| 2940 | |
| 2941 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2942 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2943 | |
| 2944 | .. data:: P_WAIT |
| 2945 | |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 2946 | Possible value for the *mode* parameter to the :func:`spawn\* <spawnl>` family of |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2947 | functions. If this is given as *mode*, the :func:`spawn\*` functions will not |
| 2948 | return until the new process has run to completion and will return the exit code |
| 2949 | of the process the run is successful, or ``-signal`` if a signal kills the |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2950 | process. |
| 2951 | |
| 2952 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2953 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2954 | |
| 2955 | .. data:: P_DETACH |
| 2956 | P_OVERLAY |
| 2957 | |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 2958 | Possible values for the *mode* parameter to the :func:`spawn\* <spawnl>` family of |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2959 | functions. These are less portable than those listed above. :const:`P_DETACH` |
| 2960 | is similar to :const:`P_NOWAIT`, but the new process is detached from the |
| 2961 | console of the calling process. If :const:`P_OVERLAY` is used, the current |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 2962 | process will be replaced; the :func:`spawn\* <spawnl>` function will not return. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2963 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2964 | Availability: Windows. |
| 2965 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2966 | |
| 2967 | .. function:: startfile(path[, operation]) |
| 2968 | |
| 2969 | Start a file with its associated application. |
| 2970 | |
| 2971 | When *operation* is not specified or ``'open'``, this acts like double-clicking |
| 2972 | the file in Windows Explorer, or giving the file name as an argument to the |
| 2973 | :program:`start` command from the interactive command shell: the file is opened |
| 2974 | with whatever application (if any) its extension is associated. |
| 2975 | |
| 2976 | When another *operation* is given, it must be a "command verb" that specifies |
| 2977 | what should be done with the file. Common verbs documented by Microsoft are |
| 2978 | ``'print'`` and ``'edit'`` (to be used on files) as well as ``'explore'`` and |
| 2979 | ``'find'`` (to be used on directories). |
| 2980 | |
| 2981 | :func:`startfile` returns as soon as the associated application is launched. |
| 2982 | There is no option to wait for the application to close, and no way to retrieve |
| 2983 | the application's exit status. The *path* parameter is relative to the current |
| 2984 | directory. If you want to use an absolute path, make sure the first character |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 2985 | is not a slash (``'/'``); the underlying Win32 :c:func:`ShellExecute` function |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2986 | doesn't work if it is. Use the :func:`os.path.normpath` function to ensure that |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2987 | the path is properly encoded for Win32. |
| 2988 | |
| 2989 | Availability: Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2990 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2991 | |
| 2992 | .. function:: system(command) |
| 2993 | |
| 2994 | Execute the command (a string) in a subshell. This is implemented by calling |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 2995 | the Standard C function :c:func:`system`, and has the same limitations. |
Georg Brandl | 8f7b427 | 2010-10-14 06:35:53 +0000 | [diff] [blame] | 2996 | Changes to :data:`sys.stdin`, etc. are not reflected in the environment of |
| 2997 | the executed command. If *command* generates any output, it will be sent to |
| 2998 | the interpreter standard output stream. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2999 | |
| 3000 | On Unix, the return value is the exit status of the process encoded in the |
Georg Brandl | 8f7b427 | 2010-10-14 06:35:53 +0000 | [diff] [blame] | 3001 | format specified for :func:`wait`. Note that POSIX does not specify the |
| 3002 | meaning of the return value of the C :c:func:`system` function, so the return |
| 3003 | value of the Python function is system-dependent. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3004 | |
Georg Brandl | 8f7b427 | 2010-10-14 06:35:53 +0000 | [diff] [blame] | 3005 | On Windows, the return value is that returned by the system shell after |
| 3006 | running *command*. The shell is given by the Windows environment variable |
| 3007 | :envvar:`COMSPEC`: it is usually :program:`cmd.exe`, which returns the exit |
| 3008 | status of the command run; on systems using a non-native shell, consult your |
| 3009 | shell documentation. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3010 | |
Georg Brandl | 8f7b427 | 2010-10-14 06:35:53 +0000 | [diff] [blame] | 3011 | The :mod:`subprocess` module provides more powerful facilities for spawning |
| 3012 | new processes and retrieving their results; using that module is preferable |
| 3013 | to using this function. See the :ref:`subprocess-replacements` section in |
| 3014 | the :mod:`subprocess` documentation for some helpful recipes. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3015 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3016 | Availability: Unix, Windows. |
| 3017 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3018 | |
| 3019 | .. function:: times() |
| 3020 | |
Larry Hastings | 605a62d | 2012-06-24 04:33:36 -0700 | [diff] [blame] | 3021 | Returns the current global process times. |
| 3022 | The return value is an object with five attributes: |
| 3023 | |
| 3024 | * :attr:`user` - user time |
| 3025 | * :attr:`system` - system time |
| 3026 | * :attr:`children_user` - user time of all child processes |
| 3027 | * :attr:`children_system` - system time of all child processes |
| 3028 | * :attr:`elapsed` - elapsed real time since a fixed point in the past |
| 3029 | |
| 3030 | For backwards compatibility, this object also behaves like a five-tuple |
| 3031 | containing :attr:`user`, :attr:`system`, :attr:`children_user`, |
| 3032 | :attr:`children_system`, and :attr:`elapsed` in that order. |
| 3033 | |
| 3034 | See the Unix manual page |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3035 | :manpage:`times(2)` or the corresponding Windows Platform API documentation. |
Larry Hastings | 605a62d | 2012-06-24 04:33:36 -0700 | [diff] [blame] | 3036 | On Windows, only :attr:`user` and :attr:`system` are known; the other |
| 3037 | attributes are zero. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3038 | |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 3039 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3040 | |
Larry Hastings | 605a62d | 2012-06-24 04:33:36 -0700 | [diff] [blame] | 3041 | .. versionchanged:: 3.3 |
| 3042 | Return type changed from a tuple to a tuple-like object |
| 3043 | with named attributes. |
| 3044 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3045 | |
| 3046 | .. function:: wait() |
| 3047 | |
| 3048 | Wait for completion of a child process, and return a tuple containing its pid |
| 3049 | and exit status indication: a 16-bit number, whose low byte is the signal number |
| 3050 | that killed the process, and whose high byte is the exit status (if the signal |
| 3051 | number is zero); the high bit of the low byte is set if a core file was |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3052 | produced. |
| 3053 | |
| 3054 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3055 | |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 3056 | .. function:: waitid(idtype, id, options) |
| 3057 | |
| 3058 | Wait for the completion of one or more child processes. |
| 3059 | *idtype* can be :data:`P_PID`, :data:`P_PGID` or :data:`P_ALL`. |
| 3060 | *id* specifies the pid to wait on. |
| 3061 | *options* is constructed from the ORing of one or more of :data:`WEXITED`, |
| 3062 | :data:`WSTOPPED` or :data:`WCONTINUED` and additionally may be ORed with |
| 3063 | :data:`WNOHANG` or :data:`WNOWAIT`. The return value is an object |
| 3064 | representing the data contained in the :c:type:`siginfo_t` structure, namely: |
| 3065 | :attr:`si_pid`, :attr:`si_uid`, :attr:`si_signo`, :attr:`si_status`, |
| 3066 | :attr:`si_code` or ``None`` if :data:`WNOHANG` is specified and there are no |
| 3067 | children in a waitable state. |
| 3068 | |
| 3069 | Availability: Unix. |
| 3070 | |
| 3071 | .. versionadded:: 3.3 |
| 3072 | |
| 3073 | .. data:: P_PID |
| 3074 | P_PGID |
| 3075 | P_ALL |
| 3076 | |
| 3077 | These are the possible values for *idtype* in :func:`waitid`. They affect |
| 3078 | how *id* is interpreted. |
| 3079 | |
| 3080 | Availability: Unix. |
| 3081 | |
| 3082 | .. versionadded:: 3.3 |
| 3083 | |
| 3084 | .. data:: WEXITED |
| 3085 | WSTOPPED |
| 3086 | WNOWAIT |
| 3087 | |
| 3088 | Flags that can be used in *options* in :func:`waitid` that specify what |
| 3089 | child signal to wait for. |
| 3090 | |
| 3091 | Availability: Unix. |
| 3092 | |
| 3093 | .. versionadded:: 3.3 |
| 3094 | |
| 3095 | |
| 3096 | .. data:: CLD_EXITED |
| 3097 | CLD_DUMPED |
| 3098 | CLD_TRAPPED |
| 3099 | CLD_CONTINUED |
| 3100 | |
| 3101 | These are the possible values for :attr:`si_code` in the result returned by |
| 3102 | :func:`waitid`. |
| 3103 | |
| 3104 | Availability: Unix. |
| 3105 | |
| 3106 | .. versionadded:: 3.3 |
| 3107 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3108 | |
| 3109 | .. function:: waitpid(pid, options) |
| 3110 | |
| 3111 | The details of this function differ on Unix and Windows. |
| 3112 | |
| 3113 | On Unix: Wait for completion of a child process given by process id *pid*, and |
| 3114 | return a tuple containing its process id and exit status indication (encoded as |
| 3115 | for :func:`wait`). The semantics of the call are affected by the value of the |
| 3116 | integer *options*, which should be ``0`` for normal operation. |
| 3117 | |
| 3118 | If *pid* is greater than ``0``, :func:`waitpid` requests status information for |
| 3119 | that specific process. If *pid* is ``0``, the request is for the status of any |
| 3120 | child in the process group of the current process. If *pid* is ``-1``, the |
| 3121 | request pertains to any child of the current process. If *pid* is less than |
| 3122 | ``-1``, status is requested for any process in the process group ``-pid`` (the |
| 3123 | absolute value of *pid*). |
| 3124 | |
Benjamin Peterson | 4cd6a95 | 2008-08-17 20:23:46 +0000 | [diff] [blame] | 3125 | An :exc:`OSError` is raised with the value of errno when the syscall |
| 3126 | returns -1. |
| 3127 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3128 | On Windows: Wait for completion of a process given by process handle *pid*, and |
| 3129 | return a tuple containing *pid*, and its exit status shifted left by 8 bits |
| 3130 | (shifting makes cross-platform use of the function easier). A *pid* less than or |
| 3131 | equal to ``0`` has no special meaning on Windows, and raises an exception. The |
| 3132 | value of integer *options* has no effect. *pid* can refer to any process whose |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 3133 | id is known, not necessarily a child process. The :func:`spawn\* <spawnl>` |
| 3134 | functions called with :const:`P_NOWAIT` return suitable process handles. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3135 | |
| 3136 | |
Ezio Melotti | ba4d8ed | 2012-11-23 19:45:52 +0200 | [diff] [blame] | 3137 | .. function:: wait3(options) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3138 | |
| 3139 | Similar to :func:`waitpid`, except no process id argument is given and a |
| 3140 | 3-element tuple containing the child's process id, exit status indication, and |
| 3141 | resource usage information is returned. Refer to :mod:`resource`.\ |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 3142 | :func:`~resource.getrusage` for details on resource usage information. The |
| 3143 | option argument is the same as that provided to :func:`waitpid` and |
| 3144 | :func:`wait4`. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3145 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3146 | Availability: Unix. |
| 3147 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3148 | |
Victor Stinner | 4195b5c | 2012-02-08 23:03:19 +0100 | [diff] [blame] | 3149 | .. function:: wait4(pid, options) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3150 | |
| 3151 | Similar to :func:`waitpid`, except a 3-element tuple, containing the child's |
| 3152 | process id, exit status indication, and resource usage information is returned. |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 3153 | Refer to :mod:`resource`.\ :func:`~resource.getrusage` for details on |
| 3154 | resource usage information. The arguments to :func:`wait4` are the same |
| 3155 | as those provided to :func:`waitpid`. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3156 | |
| 3157 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3158 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3159 | |
| 3160 | .. data:: WNOHANG |
| 3161 | |
| 3162 | The option for :func:`waitpid` to return immediately if no child process status |
| 3163 | is available immediately. The function returns ``(0, 0)`` in this case. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3164 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 3165 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3166 | |
| 3167 | |
| 3168 | .. data:: WCONTINUED |
| 3169 | |
| 3170 | This option causes child processes to be reported if they have been continued |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3171 | from a job control stop since their status was last reported. |
| 3172 | |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 3173 | Availability: some Unix systems. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3174 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3175 | |
| 3176 | .. data:: WUNTRACED |
| 3177 | |
| 3178 | This option causes child processes to be reported if they have been stopped but |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3179 | their current state has not been reported since they were stopped. |
| 3180 | |
| 3181 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3182 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3183 | |
| 3184 | The following functions take a process status code as returned by |
| 3185 | :func:`system`, :func:`wait`, or :func:`waitpid` as a parameter. They may be |
| 3186 | used to determine the disposition of a process. |
| 3187 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3188 | .. function:: WCOREDUMP(status) |
| 3189 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 3190 | Return ``True`` if a core dump was generated for the process, otherwise |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3191 | return ``False``. |
| 3192 | |
| 3193 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3194 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3195 | |
| 3196 | .. function:: WIFCONTINUED(status) |
| 3197 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 3198 | Return ``True`` if the process has been continued from a job control stop, |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3199 | otherwise return ``False``. |
| 3200 | |
| 3201 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3202 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3203 | |
| 3204 | .. function:: WIFSTOPPED(status) |
| 3205 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 3206 | Return ``True`` if the process has been stopped, otherwise return |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3207 | ``False``. |
| 3208 | |
| 3209 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3210 | |
| 3211 | |
| 3212 | .. function:: WIFSIGNALED(status) |
| 3213 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 3214 | Return ``True`` if the process exited due to a signal, otherwise return |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3215 | ``False``. |
| 3216 | |
| 3217 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3218 | |
| 3219 | |
| 3220 | .. function:: WIFEXITED(status) |
| 3221 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 3222 | Return ``True`` if the process exited using the :manpage:`exit(2)` system call, |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3223 | otherwise return ``False``. |
| 3224 | |
| 3225 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3226 | |
| 3227 | |
| 3228 | .. function:: WEXITSTATUS(status) |
| 3229 | |
| 3230 | If ``WIFEXITED(status)`` is true, return the integer parameter to the |
| 3231 | :manpage:`exit(2)` system call. Otherwise, the return value is meaningless. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3232 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 3233 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3234 | |
| 3235 | |
| 3236 | .. function:: WSTOPSIG(status) |
| 3237 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3238 | Return the signal which caused the process to stop. |
| 3239 | |
| 3240 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3241 | |
| 3242 | |
| 3243 | .. function:: WTERMSIG(status) |
| 3244 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3245 | Return the signal which caused the process to exit. |
| 3246 | |
| 3247 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3248 | |
| 3249 | |
Benjamin Peterson | 94b580d | 2011-08-02 17:30:04 -0500 | [diff] [blame] | 3250 | Interface to the scheduler |
| 3251 | -------------------------- |
| 3252 | |
| 3253 | These functions control how a process is allocated CPU time by the operating |
| 3254 | system. They are only available on some Unix platforms. For more detailed |
| 3255 | information, consult your Unix manpages. |
| 3256 | |
| 3257 | .. versionadded:: 3.3 |
| 3258 | |
Andrew Kuchling | 4921a08 | 2013-06-21 11:49:57 -0400 | [diff] [blame] | 3259 | The following scheduling policies are exposed if they are supported by the |
Benjamin Peterson | 94b580d | 2011-08-02 17:30:04 -0500 | [diff] [blame] | 3260 | operating system. |
| 3261 | |
| 3262 | .. data:: SCHED_OTHER |
| 3263 | |
| 3264 | The default scheduling policy. |
| 3265 | |
| 3266 | .. data:: SCHED_BATCH |
| 3267 | |
| 3268 | Scheduling policy for CPU-intensive processes that tries to preserve |
| 3269 | interactivity on the rest of the computer. |
| 3270 | |
| 3271 | .. data:: SCHED_IDLE |
| 3272 | |
| 3273 | Scheduling policy for extremely low priority background tasks. |
| 3274 | |
| 3275 | .. data:: SCHED_SPORADIC |
| 3276 | |
| 3277 | Scheduling policy for sporadic server programs. |
| 3278 | |
| 3279 | .. data:: SCHED_FIFO |
| 3280 | |
| 3281 | A First In First Out scheduling policy. |
| 3282 | |
| 3283 | .. data:: SCHED_RR |
| 3284 | |
| 3285 | A round-robin scheduling policy. |
| 3286 | |
| 3287 | .. data:: SCHED_RESET_ON_FORK |
| 3288 | |
| 3289 | This flag can OR'ed with any other scheduling policy. When a process with |
| 3290 | this flag set forks, its child's scheduling policy and priority are reset to |
| 3291 | the default. |
| 3292 | |
| 3293 | |
| 3294 | .. class:: sched_param(sched_priority) |
| 3295 | |
| 3296 | This class represents tunable scheduling parameters used in |
| 3297 | :func:`sched_setparam`, :func:`sched_setscheduler`, and |
| 3298 | :func:`sched_getparam`. It is immutable. |
| 3299 | |
| 3300 | At the moment, there is only one possible parameter: |
| 3301 | |
| 3302 | .. attribute:: sched_priority |
| 3303 | |
| 3304 | The scheduling priority for a scheduling policy. |
| 3305 | |
| 3306 | |
| 3307 | .. function:: sched_get_priority_min(policy) |
| 3308 | |
| 3309 | Get the minimum priority value for *policy*. *policy* is one of the |
| 3310 | scheduling policy constants above. |
| 3311 | |
| 3312 | |
| 3313 | .. function:: sched_get_priority_max(policy) |
| 3314 | |
| 3315 | Get the maximum priority value for *policy*. *policy* is one of the |
| 3316 | scheduling policy constants above. |
| 3317 | |
| 3318 | |
| 3319 | .. function:: sched_setscheduler(pid, policy, param) |
| 3320 | |
| 3321 | Set the scheduling policy for the process with PID *pid*. A *pid* of 0 means |
| 3322 | the calling process. *policy* is one of the scheduling policy constants |
| 3323 | above. *param* is a :class:`sched_param` instance. |
| 3324 | |
| 3325 | |
| 3326 | .. function:: sched_getscheduler(pid) |
| 3327 | |
| 3328 | Return the scheduling policy for the process with PID *pid*. A *pid* of 0 |
| 3329 | means the calling process. The result is one of the scheduling policy |
| 3330 | constants above. |
| 3331 | |
| 3332 | |
| 3333 | .. function:: sched_setparam(pid, param) |
| 3334 | |
| 3335 | Set a scheduling parameters for the process with PID *pid*. A *pid* of 0 means |
| 3336 | the calling process. *param* is a :class:`sched_param` instance. |
| 3337 | |
| 3338 | |
| 3339 | .. function:: sched_getparam(pid) |
| 3340 | |
| 3341 | Return the scheduling parameters as a :class:`sched_param` instance for the |
| 3342 | process with PID *pid*. A *pid* of 0 means the calling process. |
| 3343 | |
| 3344 | |
| 3345 | .. function:: sched_rr_get_interval(pid) |
| 3346 | |
| 3347 | Return the round-robin quantum in seconds for the process with PID *pid*. A |
| 3348 | *pid* of 0 means the calling process. |
| 3349 | |
| 3350 | |
| 3351 | .. function:: sched_yield() |
| 3352 | |
| 3353 | Voluntarily relinquish the CPU. |
| 3354 | |
| 3355 | |
Benjamin Peterson | 94b580d | 2011-08-02 17:30:04 -0500 | [diff] [blame] | 3356 | .. function:: sched_setaffinity(pid, mask) |
| 3357 | |
Antoine Pitrou | 8486987 | 2012-08-04 16:16:35 +0200 | [diff] [blame] | 3358 | Restrict the process with PID *pid* (or the current process if zero) to a |
| 3359 | set of CPUs. *mask* is an iterable of integers representing the set of |
| 3360 | CPUs to which the process should be restricted. |
Benjamin Peterson | 94b580d | 2011-08-02 17:30:04 -0500 | [diff] [blame] | 3361 | |
| 3362 | |
Antoine Pitrou | 8486987 | 2012-08-04 16:16:35 +0200 | [diff] [blame] | 3363 | .. function:: sched_getaffinity(pid) |
Benjamin Peterson | 94b580d | 2011-08-02 17:30:04 -0500 | [diff] [blame] | 3364 | |
Antoine Pitrou | 8486987 | 2012-08-04 16:16:35 +0200 | [diff] [blame] | 3365 | Return the set of CPUs the process with PID *pid* (or the current process |
| 3366 | if zero) is restricted to. |
Benjamin Peterson | 94b580d | 2011-08-02 17:30:04 -0500 | [diff] [blame] | 3367 | |
| 3368 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3369 | .. _os-path: |
| 3370 | |
| 3371 | Miscellaneous System Information |
| 3372 | -------------------------------- |
| 3373 | |
| 3374 | |
| 3375 | .. function:: confstr(name) |
| 3376 | |
| 3377 | Return string-valued system configuration values. *name* specifies the |
| 3378 | configuration value to retrieve; it may be a string which is the name of a |
| 3379 | defined system value; these names are specified in a number of standards (POSIX, |
| 3380 | Unix 95, Unix 98, and others). Some platforms define additional names as well. |
| 3381 | The names known to the host operating system are given as the keys of the |
| 3382 | ``confstr_names`` dictionary. For configuration variables not included in that |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3383 | mapping, passing an integer for *name* is also accepted. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3384 | |
| 3385 | If the configuration value specified by *name* isn't defined, ``None`` is |
| 3386 | returned. |
| 3387 | |
| 3388 | If *name* is a string and is not known, :exc:`ValueError` is raised. If a |
| 3389 | specific value for *name* is not supported by the host system, even if it is |
| 3390 | included in ``confstr_names``, an :exc:`OSError` is raised with |
| 3391 | :const:`errno.EINVAL` for the error number. |
| 3392 | |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 3393 | Availability: Unix. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3394 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3395 | |
| 3396 | .. data:: confstr_names |
| 3397 | |
| 3398 | Dictionary mapping names accepted by :func:`confstr` to the integer values |
| 3399 | defined for those names by the host operating system. This can be used to |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3400 | determine the set of names known to the system. |
| 3401 | |
| 3402 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3403 | |
| 3404 | |
Charles-Francois Natali | 44feda3 | 2013-05-20 14:40:46 +0200 | [diff] [blame] | 3405 | .. function:: cpu_count() |
| 3406 | |
| 3407 | Return the number of CPUs in the system. Returns None if undetermined. |
| 3408 | |
| 3409 | .. versionadded:: 3.4 |
| 3410 | |
| 3411 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3412 | .. function:: getloadavg() |
| 3413 | |
Christian Heimes | a62da1d | 2008-01-12 19:39:10 +0000 | [diff] [blame] | 3414 | Return the number of processes in the system run queue averaged over the last |
| 3415 | 1, 5, and 15 minutes or raises :exc:`OSError` if the load average was |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3416 | unobtainable. |
| 3417 | |
| 3418 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3419 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3420 | |
| 3421 | .. function:: sysconf(name) |
| 3422 | |
| 3423 | Return integer-valued system configuration values. If the configuration value |
| 3424 | specified by *name* isn't defined, ``-1`` is returned. The comments regarding |
| 3425 | the *name* parameter for :func:`confstr` apply here as well; the dictionary that |
| 3426 | provides information on the known names is given by ``sysconf_names``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3427 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 3428 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3429 | |
| 3430 | |
| 3431 | .. data:: sysconf_names |
| 3432 | |
| 3433 | Dictionary mapping names accepted by :func:`sysconf` to the integer values |
| 3434 | defined for those names by the host operating system. This can be used to |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3435 | determine the set of names known to the system. |
| 3436 | |
| 3437 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3438 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 3439 | The following data values are used to support path manipulation operations. These |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3440 | are defined for all platforms. |
| 3441 | |
| 3442 | Higher-level operations on pathnames are defined in the :mod:`os.path` module. |
| 3443 | |
| 3444 | |
| 3445 | .. data:: curdir |
| 3446 | |
| 3447 | The constant string used by the operating system to refer to the current |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 3448 | directory. This is ``'.'`` for Windows and POSIX. Also available via |
| 3449 | :mod:`os.path`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3450 | |
| 3451 | |
| 3452 | .. data:: pardir |
| 3453 | |
| 3454 | The constant string used by the operating system to refer to the parent |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 3455 | directory. This is ``'..'`` for Windows and POSIX. Also available via |
| 3456 | :mod:`os.path`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3457 | |
| 3458 | |
| 3459 | .. data:: sep |
| 3460 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 3461 | The character used by the operating system to separate pathname components. |
| 3462 | This is ``'/'`` for POSIX and ``'\\'`` for Windows. Note that knowing this |
| 3463 | is not sufficient to be able to parse or concatenate pathnames --- use |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3464 | :func:`os.path.split` and :func:`os.path.join` --- but it is occasionally |
| 3465 | useful. Also available via :mod:`os.path`. |
| 3466 | |
| 3467 | |
| 3468 | .. data:: altsep |
| 3469 | |
| 3470 | An alternative character used by the operating system to separate pathname |
| 3471 | components, or ``None`` if only one separator character exists. This is set to |
| 3472 | ``'/'`` on Windows systems where ``sep`` is a backslash. Also available via |
| 3473 | :mod:`os.path`. |
| 3474 | |
| 3475 | |
| 3476 | .. data:: extsep |
| 3477 | |
| 3478 | The character which separates the base filename from the extension; for example, |
| 3479 | the ``'.'`` in :file:`os.py`. Also available via :mod:`os.path`. |
| 3480 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3481 | |
| 3482 | .. data:: pathsep |
| 3483 | |
| 3484 | The character conventionally used by the operating system to separate search |
| 3485 | path components (as in :envvar:`PATH`), such as ``':'`` for POSIX or ``';'`` for |
| 3486 | Windows. Also available via :mod:`os.path`. |
| 3487 | |
| 3488 | |
| 3489 | .. data:: defpath |
| 3490 | |
Serhiy Storchaka | dab8354 | 2013-10-13 20:12:43 +0300 | [diff] [blame] | 3491 | The default search path used by :func:`exec\*p\* <execl>` and |
| 3492 | :func:`spawn\*p\* <spawnl>` if the environment doesn't have a ``'PATH'`` |
| 3493 | key. Also available via :mod:`os.path`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3494 | |
| 3495 | |
| 3496 | .. data:: linesep |
| 3497 | |
| 3498 | The string used to separate (or, rather, terminate) lines on the current |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 3499 | platform. This may be a single character, such as ``'\n'`` for POSIX, or |
| 3500 | multiple characters, for example, ``'\r\n'`` for Windows. Do not use |
| 3501 | *os.linesep* as a line terminator when writing files opened in text mode (the |
| 3502 | default); use a single ``'\n'`` instead, on all platforms. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3503 | |
| 3504 | |
| 3505 | .. data:: devnull |
| 3506 | |
Georg Brandl | 850a990 | 2010-05-21 22:04:32 +0000 | [diff] [blame] | 3507 | The file path of the null device. For example: ``'/dev/null'`` for |
| 3508 | POSIX, ``'nul'`` for Windows. Also available via :mod:`os.path`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3509 | |
Andrew Kuchling | 4921a08 | 2013-06-21 11:49:57 -0400 | [diff] [blame] | 3510 | .. data:: RTLD_LAZY |
| 3511 | RTLD_NOW |
| 3512 | RTLD_GLOBAL |
| 3513 | RTLD_LOCAL |
| 3514 | RTLD_NODELETE |
| 3515 | RTLD_NOLOAD |
| 3516 | RTLD_DEEPBIND |
| 3517 | |
| 3518 | Flags for use with the :func:`~sys.setdlopenflags` and |
| 3519 | :func:`~sys.getdlopenflags` functions. See the Unix manual page |
| 3520 | :manpage:`dlopen(3)` for what the different flags mean. |
| 3521 | |
| 3522 | .. versionadded:: 3.3 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3523 | |
| 3524 | .. _os-miscfunc: |
| 3525 | |
| 3526 | Miscellaneous Functions |
| 3527 | ----------------------- |
| 3528 | |
| 3529 | |
| 3530 | .. function:: urandom(n) |
| 3531 | |
| 3532 | Return a string of *n* random bytes suitable for cryptographic use. |
| 3533 | |
| 3534 | This function returns random bytes from an OS-specific randomness source. The |
| 3535 | returned data should be unpredictable enough for cryptographic applications, |
Georg Brandl | f62445a | 2012-06-24 13:31:20 +0200 | [diff] [blame] | 3536 | though its exact quality depends on the OS implementation. On a Unix-like |
Georg Brandl | c6a2c9b | 2013-10-06 18:43:19 +0200 | [diff] [blame] | 3537 | system this will query ``/dev/urandom``, and on Windows it will use |
| 3538 | ``CryptGenRandom()``. If a randomness source is not found, |
| 3539 | :exc:`NotImplementedError` will be raised. |
Andrew Svetlov | 03cb99c | 2012-10-16 13:15:06 +0300 | [diff] [blame] | 3540 | |
Andrew Svetlov | 2bfe386 | 2012-10-16 13:52:25 +0300 | [diff] [blame] | 3541 | For an easy-to-use interface to the random number generator |
| 3542 | provided by your platform, please see :class:`random.SystemRandom`. |