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 |
| 56 | names have currently been registered: ``'posix'``, ``'nt'``, ``'mac'``, |
| 57 | ``'os2'``, ``'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: |
| 68 | |
| 69 | File Names, Command Line Arguments, and Environment Variables |
| 70 | ------------------------------------------------------------- |
| 71 | |
Georg Brandl | 67b21b7 | 2010-08-17 15:07:14 +0000 | [diff] [blame] | 72 | In Python, file names, command line arguments, and environment variables are |
| 73 | represented using the string type. On some systems, decoding these strings to |
| 74 | and from bytes is necessary before passing them to the operating system. Python |
| 75 | uses the file system encoding to perform this conversion (see |
| 76 | :func:`sys.getfilesystemencoding`). |
Martin v. Löwis | 011e842 | 2009-05-05 04:43:17 +0000 | [diff] [blame] | 77 | |
| 78 | .. versionchanged:: 3.1 |
Georg Brandl | 67b21b7 | 2010-08-17 15:07:14 +0000 | [diff] [blame] | 79 | On some systems, conversion using the file system encoding may fail. In this |
| 80 | case, Python uses the ``surrogateescape`` encoding error handler, which means |
| 81 | that undecodable bytes are replaced by a Unicode character U+DCxx on |
| 82 | 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] | 83 | |
| 84 | |
Georg Brandl | 67b21b7 | 2010-08-17 15:07:14 +0000 | [diff] [blame] | 85 | The file system encoding must guarantee to successfully decode all bytes |
| 86 | below 128. If the file system encoding fails to provide this guarantee, API |
| 87 | functions may raise UnicodeErrors. |
Martin v. Löwis | 011e842 | 2009-05-05 04:43:17 +0000 | [diff] [blame] | 88 | |
| 89 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 90 | .. _os-procinfo: |
| 91 | |
| 92 | Process Parameters |
| 93 | ------------------ |
| 94 | |
| 95 | These functions and data items provide information and operate on the current |
| 96 | process and user. |
| 97 | |
| 98 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 99 | .. function:: ctermid() |
| 100 | |
| 101 | Return the filename corresponding to the controlling terminal of the process. |
| 102 | |
| 103 | Availability: Unix. |
| 104 | |
| 105 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 106 | .. data:: environ |
| 107 | |
| 108 | A mapping object representing the string environment. For example, |
| 109 | ``environ['HOME']`` is the pathname of your home directory (on some platforms), |
| 110 | and is equivalent to ``getenv("HOME")`` in C. |
| 111 | |
| 112 | This mapping is captured the first time the :mod:`os` module is imported, |
| 113 | typically during Python startup as part of processing :file:`site.py`. Changes |
| 114 | to the environment made after this time are not reflected in ``os.environ``, |
| 115 | except for changes made by modifying ``os.environ`` directly. |
| 116 | |
| 117 | If the platform supports the :func:`putenv` function, this mapping may be used |
| 118 | to modify the environment as well as query the environment. :func:`putenv` will |
| 119 | be called automatically when the mapping is modified. |
| 120 | |
Victor Stinner | 84ae118 | 2010-05-06 22:05:07 +0000 | [diff] [blame] | 121 | On Unix, keys and values use :func:`sys.getfilesystemencoding` and |
| 122 | ``'surrogateescape'`` error handler. Use :data:`environb` if you would like |
| 123 | to use a different encoding. |
| 124 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 125 | .. note:: |
| 126 | |
| 127 | Calling :func:`putenv` directly does not change ``os.environ``, so it's better |
| 128 | to modify ``os.environ``. |
| 129 | |
| 130 | .. note:: |
| 131 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 132 | On some platforms, including FreeBSD and Mac OS X, setting ``environ`` may |
| 133 | cause memory leaks. Refer to the system documentation for |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 134 | :c:func:`putenv`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 135 | |
| 136 | If :func:`putenv` is not provided, a modified copy of this mapping may be |
| 137 | passed to the appropriate process-creation functions to cause child processes |
| 138 | to use a modified environment. |
| 139 | |
Georg Brandl | 9afde1c | 2007-11-01 20:32:30 +0000 | [diff] [blame] | 140 | 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] | 141 | this mapping to unset environment variables. :func:`unsetenv` will be called |
Georg Brandl | 9afde1c | 2007-11-01 20:32:30 +0000 | [diff] [blame] | 142 | automatically when an item is deleted from ``os.environ``, and when |
| 143 | one of the :meth:`pop` or :meth:`clear` methods is called. |
| 144 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 145 | |
Victor Stinner | 84ae118 | 2010-05-06 22:05:07 +0000 | [diff] [blame] | 146 | .. data:: environb |
| 147 | |
| 148 | Bytes version of :data:`environ`: a mapping object representing the |
| 149 | environment as byte strings. :data:`environ` and :data:`environb` are |
| 150 | synchronized (modify :data:`environb` updates :data:`environ`, and vice |
| 151 | versa). |
| 152 | |
Victor Stinner | b745a74 | 2010-05-18 17:17:23 +0000 | [diff] [blame] | 153 | :data:`environb` is only available if :data:`supports_bytes_environ` is |
| 154 | True. |
Victor Stinner | 84ae118 | 2010-05-06 22:05:07 +0000 | [diff] [blame] | 155 | |
Benjamin Peterson | 662c74f | 2010-05-06 22:09:03 +0000 | [diff] [blame] | 156 | .. versionadded:: 3.2 |
| 157 | |
Victor Stinner | 84ae118 | 2010-05-06 22:05:07 +0000 | [diff] [blame] | 158 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 159 | .. function:: chdir(path) |
| 160 | fchdir(fd) |
| 161 | getcwd() |
| 162 | :noindex: |
| 163 | |
| 164 | These functions are described in :ref:`os-file-dir`. |
| 165 | |
| 166 | |
Victor Stinner | e8d5145 | 2010-08-19 01:05:19 +0000 | [diff] [blame] | 167 | .. function:: fsencode(filename) |
Victor Stinner | 449c466 | 2010-05-08 11:10:09 +0000 | [diff] [blame] | 168 | |
Victor Stinner | e8d5145 | 2010-08-19 01:05:19 +0000 | [diff] [blame] | 169 | Encode *filename* to the filesystem encoding with ``'surrogateescape'`` |
Victor Stinner | 62165d6 | 2010-10-09 10:34:37 +0000 | [diff] [blame] | 170 | error handler, or ``'strict'`` on Windows; return :class:`bytes` unchanged. |
Victor Stinner | e8d5145 | 2010-08-19 01:05:19 +0000 | [diff] [blame] | 171 | |
Antoine Pitrou | a305ca7 | 2010-09-25 22:12:00 +0000 | [diff] [blame] | 172 | :func:`fsdecode` is the reverse function. |
Victor Stinner | e8d5145 | 2010-08-19 01:05:19 +0000 | [diff] [blame] | 173 | |
| 174 | .. versionadded:: 3.2 |
| 175 | |
| 176 | |
| 177 | .. function:: fsdecode(filename) |
| 178 | |
| 179 | Decode *filename* from the filesystem encoding with ``'surrogateescape'`` |
Victor Stinner | 62165d6 | 2010-10-09 10:34:37 +0000 | [diff] [blame] | 180 | error handler, or ``'strict'`` on Windows; return :class:`str` unchanged. |
Victor Stinner | e8d5145 | 2010-08-19 01:05:19 +0000 | [diff] [blame] | 181 | |
| 182 | :func:`fsencode` is the reverse function. |
Victor Stinner | 449c466 | 2010-05-08 11:10:09 +0000 | [diff] [blame] | 183 | |
| 184 | .. versionadded:: 3.2 |
| 185 | |
| 186 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 187 | .. function:: getenv(key, default=None) |
| 188 | |
| 189 | Return the value of the environment variable *key* if it exists, or |
| 190 | *default* if it doesn't. *key*, *default* and the result are str. |
| 191 | |
| 192 | On Unix, keys and values are decoded with :func:`sys.getfilesystemencoding` |
| 193 | and ``'surrogateescape'`` error handler. Use :func:`os.getenvb` if you |
| 194 | would like to use a different encoding. |
| 195 | |
| 196 | Availability: most flavors of Unix, Windows. |
| 197 | |
| 198 | |
| 199 | .. function:: getenvb(key, default=None) |
| 200 | |
| 201 | Return the value of the environment variable *key* if it exists, or |
| 202 | *default* if it doesn't. *key*, *default* and the result are bytes. |
| 203 | |
| 204 | Availability: most flavors of Unix. |
| 205 | |
| 206 | .. versionadded:: 3.2 |
| 207 | |
| 208 | |
Gregory P. Smith | b6e8c7e | 2010-02-27 07:22:22 +0000 | [diff] [blame] | 209 | .. function:: get_exec_path(env=None) |
| 210 | |
| 211 | Returns the list of directories that will be searched for a named |
| 212 | executable, similar to a shell, when launching a process. |
| 213 | *env*, when specified, should be an environment variable dictionary |
| 214 | to lookup the PATH in. |
| 215 | By default, when *env* is None, :data:`environ` is used. |
| 216 | |
| 217 | .. versionadded:: 3.2 |
| 218 | |
| 219 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 220 | .. function:: getegid() |
| 221 | |
| 222 | 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] | 223 | "set id" bit on the file being executed in the current process. |
| 224 | |
| 225 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 226 | |
| 227 | |
| 228 | .. function:: geteuid() |
| 229 | |
| 230 | .. index:: single: user; effective id |
| 231 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 232 | Return the current process's effective user id. |
| 233 | |
| 234 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 235 | |
| 236 | |
| 237 | .. function:: getgid() |
| 238 | |
| 239 | .. index:: single: process; group |
| 240 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 241 | Return the real group id of the current process. |
| 242 | |
| 243 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 244 | |
| 245 | |
Ross Lagerwall | b0ae53d | 2011-06-10 07:30:30 +0200 | [diff] [blame] | 246 | .. function:: getgrouplist(user, group) |
| 247 | |
| 248 | Return list of group ids that *user* belongs to. If *group* is not in the |
| 249 | list, it is included; typically, *group* is specified as the group ID |
| 250 | field from the password record for *user*. |
| 251 | |
| 252 | Availability: Unix. |
| 253 | |
| 254 | .. versionadded:: 3.3 |
| 255 | |
| 256 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 257 | .. function:: getgroups() |
| 258 | |
| 259 | Return list of supplemental group ids associated with the current process. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 260 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 261 | Availability: Unix. |
| 262 | |
Ned Deily | 2e20968 | 2012-04-30 11:14:02 -0700 | [diff] [blame] | 263 | .. note:: On Mac OS X, :func:`getgroups` behavior differs somewhat from |
| 264 | other Unix platforms. If the Python interpreter was built with a |
| 265 | deployment target of :const:`10.5` or earlier, :func:`getgroups` returns |
| 266 | the list of effective group ids associated with the current user process; |
| 267 | this list is limited to a system-defined number of entries, typically 16, |
| 268 | and may be modified by calls to :func:`setgroups` if suitably privileged. |
| 269 | If built with a deployment target greater than :const:`10.5`, |
| 270 | :func:`getgroups` returns the current group access list for the user |
| 271 | associated with the effective user id of the process; the group access |
| 272 | list may change over the lifetime of the process, it is not affected by |
| 273 | calls to :func:`setgroups`, and its length is not limited to 16. The |
| 274 | deployment target value, :const:`MACOSX_DEPLOYMENT_TARGET`, can be |
| 275 | obtained with :func:`sysconfig.get_config_var`. |
| 276 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 277 | |
| 278 | .. function:: getlogin() |
| 279 | |
| 280 | Return the name of the user logged in on the controlling terminal of the |
Brian Curtin | e8e4b3b | 2010-09-23 20:04:14 +0000 | [diff] [blame] | 281 | process. For most purposes, it is more useful to use the environment variables |
| 282 | :envvar:`LOGNAME` or :envvar:`USERNAME` to find out who the user is, or |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 283 | ``pwd.getpwuid(os.getuid())[0]`` to get the login name of the currently |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 284 | effective user id. |
| 285 | |
Brian Curtin | e8e4b3b | 2010-09-23 20:04:14 +0000 | [diff] [blame] | 286 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 287 | |
| 288 | |
| 289 | .. function:: getpgid(pid) |
| 290 | |
| 291 | 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] | 292 | the process group id of the current process is returned. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 293 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 294 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 295 | |
| 296 | .. function:: getpgrp() |
| 297 | |
| 298 | .. index:: single: process; group |
| 299 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 300 | Return the id of the current process group. |
| 301 | |
| 302 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 303 | |
| 304 | |
| 305 | .. function:: getpid() |
| 306 | |
| 307 | .. index:: single: process; id |
| 308 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 309 | Return the current process id. |
| 310 | |
| 311 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 312 | |
| 313 | |
| 314 | .. function:: getppid() |
| 315 | |
| 316 | .. index:: single: process; id of parent |
| 317 | |
Amaury Forgeot d'Arc | 4b6fdf3 | 2010-09-07 21:31:17 +0000 | [diff] [blame] | 318 | Return the parent's process id. When the parent process has exited, on Unix |
| 319 | the id returned is the one of the init process (1), on Windows it is still |
| 320 | the same id, which may be already reused by another process. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 321 | |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 322 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 323 | |
Amaury Forgeot d'Arc | 4b6fdf3 | 2010-09-07 21:31:17 +0000 | [diff] [blame] | 324 | .. versionchanged:: 3.2 |
| 325 | Added support for Windows. |
Georg Brandl | 1b83a45 | 2009-11-28 11:12:26 +0000 | [diff] [blame] | 326 | |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 327 | |
Giampaolo Rodolà | 18e8bcb | 2011-02-25 20:57:54 +0000 | [diff] [blame] | 328 | .. function:: getpriority(which, who) |
| 329 | |
| 330 | .. index:: single: process; scheduling priority |
| 331 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 332 | Get program scheduling priority. The value *which* is one of |
Giampaolo Rodolà | 18e8bcb | 2011-02-25 20:57:54 +0000 | [diff] [blame] | 333 | :const:`PRIO_PROCESS`, :const:`PRIO_PGRP`, or :const:`PRIO_USER`, and *who* |
| 334 | is interpreted relative to *which* (a process identifier for |
| 335 | :const:`PRIO_PROCESS`, process group identifier for :const:`PRIO_PGRP`, and a |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 336 | user ID for :const:`PRIO_USER`). A zero value for *who* denotes |
Giampaolo Rodolà | 18e8bcb | 2011-02-25 20:57:54 +0000 | [diff] [blame] | 337 | (respectively) the calling process, the process group of the calling process, |
| 338 | or the real user ID of the calling process. |
| 339 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 340 | Availability: Unix. |
Giampaolo Rodolà | 18e8bcb | 2011-02-25 20:57:54 +0000 | [diff] [blame] | 341 | |
| 342 | .. versionadded:: 3.3 |
| 343 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 344 | |
| 345 | .. data:: PRIO_PROCESS |
| 346 | PRIO_PGRP |
| 347 | PRIO_USER |
| 348 | |
| 349 | Parameters for the :func:`getpriority` and :func:`setpriority` functions. |
| 350 | |
| 351 | Availability: Unix. |
| 352 | |
| 353 | .. versionadded:: 3.3 |
| 354 | |
| 355 | |
Gregory P. Smith | cf02c6a | 2009-11-27 17:54:17 +0000 | [diff] [blame] | 356 | .. function:: getresuid() |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 357 | |
| 358 | Return a tuple (ruid, euid, suid) denoting the current process's |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 359 | real, effective, and saved user ids. |
| 360 | |
| 361 | Availability: Unix. |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 362 | |
Georg Brandl | 1b83a45 | 2009-11-28 11:12:26 +0000 | [diff] [blame] | 363 | .. versionadded:: 3.2 |
| 364 | |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 365 | |
Gregory P. Smith | cf02c6a | 2009-11-27 17:54:17 +0000 | [diff] [blame] | 366 | .. function:: getresgid() |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 367 | |
| 368 | Return a tuple (rgid, egid, sgid) denoting the current process's |
Georg Brandl | a9b51d2 | 2010-09-05 17:07:12 +0000 | [diff] [blame] | 369 | real, effective, and saved group ids. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 370 | |
| 371 | Availability: Unix. |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 372 | |
Georg Brandl | 1b83a45 | 2009-11-28 11:12:26 +0000 | [diff] [blame] | 373 | .. versionadded:: 3.2 |
| 374 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 375 | |
| 376 | .. function:: getuid() |
| 377 | |
| 378 | .. index:: single: user; id |
| 379 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 380 | Return the current process's user id. |
| 381 | |
| 382 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 383 | |
| 384 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 385 | .. function:: initgroups(username, gid) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 386 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 387 | Call the system initgroups() to initialize the group access list with all of |
| 388 | the groups of which the specified username is a member, plus the specified |
| 389 | group id. |
Giampaolo Rodolà | 18e8bcb | 2011-02-25 20:57:54 +0000 | [diff] [blame] | 390 | |
| 391 | Availability: Unix. |
| 392 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 393 | .. versionadded:: 3.2 |
| 394 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 395 | |
Georg Brandl | 1824415 | 2009-09-02 20:34:52 +0000 | [diff] [blame] | 396 | .. function:: putenv(key, value) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 397 | |
| 398 | .. index:: single: environment variables; setting |
| 399 | |
Georg Brandl | 1824415 | 2009-09-02 20:34:52 +0000 | [diff] [blame] | 400 | Set the environment variable named *key* to the string *value*. Such |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 401 | changes to the environment affect subprocesses started with :func:`os.system`, |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 402 | :func:`popen` or :func:`fork` and :func:`execv`. |
| 403 | |
| 404 | Availability: most flavors of Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 405 | |
| 406 | .. note:: |
| 407 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 408 | On some platforms, including FreeBSD and Mac OS X, setting ``environ`` may |
| 409 | cause memory leaks. Refer to the system documentation for putenv. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 410 | |
| 411 | When :func:`putenv` is supported, assignments to items in ``os.environ`` are |
| 412 | automatically translated into corresponding calls to :func:`putenv`; however, |
| 413 | calls to :func:`putenv` don't update ``os.environ``, so it is actually |
| 414 | preferable to assign to items of ``os.environ``. |
| 415 | |
| 416 | |
| 417 | .. function:: setegid(egid) |
| 418 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 419 | Set the current process's effective group id. |
| 420 | |
| 421 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 422 | |
| 423 | |
| 424 | .. function:: seteuid(euid) |
| 425 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 426 | Set the current process's effective user id. |
| 427 | |
| 428 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 429 | |
| 430 | |
| 431 | .. function:: setgid(gid) |
| 432 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 433 | Set the current process' group id. |
| 434 | |
| 435 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 436 | |
| 437 | |
| 438 | .. function:: setgroups(groups) |
| 439 | |
| 440 | Set the list of supplemental group ids associated with the current process to |
| 441 | *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] | 442 | identifying a group. This operation is typically available only to the superuser. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 443 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 444 | Availability: Unix. |
| 445 | |
Ned Deily | 2e20968 | 2012-04-30 11:14:02 -0700 | [diff] [blame] | 446 | .. note:: On Mac OS X, the length of *groups* may not exceed the |
| 447 | system-defined maximum number of effective group ids, typically 16. |
| 448 | See the documentation for :func:`getgroups` for cases where it may not |
| 449 | return the same group list set by calling setgroups(). |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 450 | |
| 451 | .. function:: setpgrp() |
| 452 | |
Andrew Svetlov | a2fe334 | 2012-08-11 21:14:08 +0300 | [diff] [blame] | 453 | 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] | 454 | 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] | 455 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 456 | Availability: Unix. |
| 457 | |
| 458 | |
| 459 | .. function:: setpgid(pid, pgrp) |
| 460 | |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 461 | 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] | 462 | 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] | 463 | for the semantics. |
| 464 | |
| 465 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 466 | |
| 467 | |
Giampaolo Rodolà | 18e8bcb | 2011-02-25 20:57:54 +0000 | [diff] [blame] | 468 | .. function:: setpriority(which, who, priority) |
| 469 | |
| 470 | .. index:: single: process; scheduling priority |
| 471 | |
| 472 | Set program scheduling priority. The value *which* is one of |
| 473 | :const:`PRIO_PROCESS`, :const:`PRIO_PGRP`, or :const:`PRIO_USER`, and *who* |
| 474 | is interpreted relative to *which* (a process identifier for |
| 475 | :const:`PRIO_PROCESS`, process group identifier for :const:`PRIO_PGRP`, and a |
| 476 | user ID for :const:`PRIO_USER`). A zero value for *who* denotes |
| 477 | (respectively) the calling process, the process group of the calling process, |
| 478 | or the real user ID of the calling process. |
| 479 | *priority* is a value in the range -20 to 19. The default priority is 0; |
| 480 | lower priorities cause more favorable scheduling. |
| 481 | |
| 482 | Availability: Unix |
| 483 | |
| 484 | .. versionadded:: 3.3 |
| 485 | |
| 486 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 487 | .. function:: setregid(rgid, egid) |
| 488 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 489 | Set the current process's real and effective group ids. |
| 490 | |
| 491 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 492 | |
Georg Brandl | 1b83a45 | 2009-11-28 11:12:26 +0000 | [diff] [blame] | 493 | |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 494 | .. function:: setresgid(rgid, egid, sgid) |
| 495 | |
| 496 | Set the current process's real, effective, and saved group ids. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 497 | |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 498 | Availability: Unix. |
| 499 | |
Georg Brandl | 1b83a45 | 2009-11-28 11:12:26 +0000 | [diff] [blame] | 500 | .. versionadded:: 3.2 |
| 501 | |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 502 | |
| 503 | .. function:: setresuid(ruid, euid, suid) |
| 504 | |
| 505 | Set the current process's real, effective, and saved user ids. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 506 | |
Georg Brandl | 6faee4e | 2010-09-21 14:48:28 +0000 | [diff] [blame] | 507 | Availability: Unix. |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 508 | |
Georg Brandl | 1b83a45 | 2009-11-28 11:12:26 +0000 | [diff] [blame] | 509 | .. versionadded:: 3.2 |
| 510 | |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 511 | |
| 512 | .. function:: setreuid(ruid, euid) |
| 513 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 514 | Set the current process's real and effective user ids. |
| 515 | |
| 516 | Availability: Unix. |
Martin v. Löwis | 7aed61a | 2009-11-27 14:09:49 +0000 | [diff] [blame] | 517 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 518 | |
| 519 | .. function:: getsid(pid) |
| 520 | |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 521 | 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] | 522 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 523 | Availability: Unix. |
| 524 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 525 | |
| 526 | .. function:: setsid() |
| 527 | |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 528 | 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] | 529 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 530 | Availability: Unix. |
| 531 | |
| 532 | |
| 533 | .. function:: setuid(uid) |
| 534 | |
| 535 | .. index:: single: user; id, setting |
| 536 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 537 | Set the current process's user id. |
| 538 | |
| 539 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 540 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 541 | |
Christian Heimes | 5b5e81c | 2007-12-31 16:14:33 +0000 | [diff] [blame] | 542 | .. placed in this section since it relates to errno.... a little weak |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 543 | .. function:: strerror(code) |
| 544 | |
| 545 | Return the error message corresponding to the error code in *code*. |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 546 | On platforms where :c:func:`strerror` returns ``NULL`` when given an unknown |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 547 | error number, :exc:`ValueError` is raised. |
| 548 | |
| 549 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 550 | |
| 551 | |
Victor Stinner | b745a74 | 2010-05-18 17:17:23 +0000 | [diff] [blame] | 552 | .. data:: supports_bytes_environ |
| 553 | |
| 554 | True if the native OS type of the environment is bytes (eg. False on |
| 555 | Windows). |
| 556 | |
Victor Stinner | 8fddc9e | 2010-05-18 17:24:09 +0000 | [diff] [blame] | 557 | .. versionadded:: 3.2 |
| 558 | |
Victor Stinner | b745a74 | 2010-05-18 17:17:23 +0000 | [diff] [blame] | 559 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 560 | .. function:: umask(mask) |
| 561 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 562 | Set the current numeric umask and return the previous umask. |
| 563 | |
| 564 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 565 | |
| 566 | |
| 567 | .. function:: uname() |
| 568 | |
| 569 | .. index:: |
| 570 | single: gethostname() (in module socket) |
| 571 | single: gethostbyaddr() (in module socket) |
| 572 | |
Larry Hastings | 605a62d | 2012-06-24 04:33:36 -0700 | [diff] [blame] | 573 | Returns information identifying the current operating system. |
| 574 | The return value is an object with five attributes: |
| 575 | |
| 576 | * :attr:`sysname` - operating system name |
| 577 | * :attr:`nodename` - name of machine on network (implementation-defined) |
| 578 | * :attr:`release` - operating system release |
| 579 | * :attr:`version` - operating system version |
| 580 | * :attr:`machine` - hardware identifier |
| 581 | |
| 582 | For backwards compatibility, this object is also iterable, behaving |
| 583 | like a five-tuple containing :attr:`sysname`, :attr:`nodename`, |
| 584 | :attr:`release`, :attr:`version`, and :attr:`machine` |
| 585 | in that order. |
| 586 | |
| 587 | Some systems truncate :attr:`nodename` to 8 characters or to the |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 588 | leading component; a better way to get the hostname is |
| 589 | :func:`socket.gethostname` or even |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 590 | ``socket.gethostbyaddr(socket.gethostname())``. |
| 591 | |
| 592 | Availability: recent flavors of Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 593 | |
Larry Hastings | 605a62d | 2012-06-24 04:33:36 -0700 | [diff] [blame] | 594 | .. versionchanged:: 3.3 |
| 595 | Return type changed from a tuple to a tuple-like object |
| 596 | with named attributes. |
| 597 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 598 | |
Georg Brandl | 1824415 | 2009-09-02 20:34:52 +0000 | [diff] [blame] | 599 | .. function:: unsetenv(key) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 600 | |
| 601 | .. index:: single: environment variables; deleting |
| 602 | |
Georg Brandl | 1824415 | 2009-09-02 20:34:52 +0000 | [diff] [blame] | 603 | Unset (delete) the environment variable named *key*. Such changes to the |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 604 | environment affect subprocesses started with :func:`os.system`, :func:`popen` or |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 605 | :func:`fork` and :func:`execv`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 606 | |
| 607 | When :func:`unsetenv` is supported, deletion of items in ``os.environ`` is |
| 608 | automatically translated into a corresponding call to :func:`unsetenv`; however, |
| 609 | calls to :func:`unsetenv` don't update ``os.environ``, so it is actually |
| 610 | preferable to delete items of ``os.environ``. |
| 611 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 612 | Availability: most flavors of Unix, Windows. |
| 613 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 614 | |
| 615 | .. _os-newstreams: |
| 616 | |
| 617 | File Object Creation |
| 618 | -------------------- |
| 619 | |
Georg Brandl | a570e98 | 2012-06-24 13:26:22 +0200 | [diff] [blame] | 620 | This function creates new :term:`file objects <file object>`. (See also |
Georg Brandl | b2462e2 | 2012-06-24 13:24:56 +0200 | [diff] [blame] | 621 | :func:`~os.open` for opening file descriptors.) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 622 | |
| 623 | |
Petri Lehtinen | 1a01ebc | 2012-05-24 21:44:07 +0300 | [diff] [blame] | 624 | .. function:: fdopen(fd, *args, **kwargs) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 625 | |
Georg Brandl | b2462e2 | 2012-06-24 13:24:56 +0200 | [diff] [blame] | 626 | Return an open file object connected to the file descriptor *fd*. This is an |
| 627 | alias of the :func:`open` built-in function and accepts the same arguments. |
| 628 | The only difference is that the first argument of :func:`fdopen` must always |
| 629 | be an integer. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 630 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 631 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 632 | .. _os-fd-ops: |
| 633 | |
| 634 | File Descriptor Operations |
| 635 | -------------------------- |
| 636 | |
| 637 | These functions operate on I/O streams referenced using file descriptors. |
| 638 | |
| 639 | File descriptors are small integers corresponding to a file that has been opened |
| 640 | by the current process. For example, standard input is usually file descriptor |
| 641 | 0, standard output is 1, and standard error is 2. Further files opened by a |
| 642 | process will then be assigned 3, 4, 5, and so forth. The name "file descriptor" |
| 643 | is slightly deceptive; on Unix platforms, sockets and pipes are also referenced |
| 644 | by file descriptors. |
| 645 | |
Benjamin Peterson | 08bf91c | 2010-04-11 16:12:57 +0000 | [diff] [blame] | 646 | The :meth:`~file.fileno` method can be used to obtain the file descriptor |
Antoine Pitrou | 11cb961 | 2010-09-15 11:11:28 +0000 | [diff] [blame] | 647 | 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] | 648 | descriptor directly will bypass the file object methods, ignoring aspects such |
| 649 | as internal buffering of data. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 650 | |
Antoine Pitrou | f65132d | 2011-02-25 23:25:17 +0000 | [diff] [blame] | 651 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 652 | .. function:: close(fd) |
| 653 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 654 | Close file descriptor *fd*. |
| 655 | |
| 656 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 657 | |
| 658 | .. note:: |
| 659 | |
| 660 | 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] | 661 | 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] | 662 | 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] | 663 | :func:`fdopen`, use its :meth:`~file.close` method. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 664 | |
| 665 | |
Christian Heimes | fdab48e | 2008-01-20 09:06:41 +0000 | [diff] [blame] | 666 | .. function:: closerange(fd_low, fd_high) |
| 667 | |
| 668 | Close all file descriptors from *fd_low* (inclusive) to *fd_high* (exclusive), |
Georg Brandl | b1a1ac0 | 2012-06-24 11:54:07 +0200 | [diff] [blame] | 669 | ignoring errors. Equivalent to (but much faster than):: |
Christian Heimes | fdab48e | 2008-01-20 09:06:41 +0000 | [diff] [blame] | 670 | |
Georg Brandl | c9a5a0e | 2009-09-01 07:34:27 +0000 | [diff] [blame] | 671 | for fd in range(fd_low, fd_high): |
Christian Heimes | fdab48e | 2008-01-20 09:06:41 +0000 | [diff] [blame] | 672 | try: |
| 673 | os.close(fd) |
| 674 | except OSError: |
| 675 | pass |
| 676 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 677 | Availability: Unix, Windows. |
| 678 | |
Christian Heimes | fdab48e | 2008-01-20 09:06:41 +0000 | [diff] [blame] | 679 | |
Georg Brandl | 81f1130 | 2007-12-21 08:45:42 +0000 | [diff] [blame] | 680 | .. function:: device_encoding(fd) |
| 681 | |
| 682 | Return a string describing the encoding of the device associated with *fd* |
| 683 | if it is connected to a terminal; else return :const:`None`. |
| 684 | |
| 685 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 686 | .. function:: dup(fd) |
| 687 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 688 | Return a duplicate of file descriptor *fd*. |
| 689 | |
| 690 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 691 | |
| 692 | |
| 693 | .. function:: dup2(fd, fd2) |
| 694 | |
| 695 | Duplicate file descriptor *fd* to *fd2*, closing the latter first if necessary. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 696 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 697 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 698 | |
| 699 | |
Christian Heimes | 4e30a84 | 2007-11-30 22:12:06 +0000 | [diff] [blame] | 700 | .. function:: fchmod(fd, mode) |
| 701 | |
Georg Brandl | b9df00c | 2012-06-24 12:38:14 +0200 | [diff] [blame] | 702 | 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] | 703 | 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] | 704 | is equivalent to ``os.chmod(fd, mode)``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 705 | |
| 706 | Availability: Unix. |
Christian Heimes | 4e30a84 | 2007-11-30 22:12:06 +0000 | [diff] [blame] | 707 | |
| 708 | |
| 709 | .. function:: fchown(fd, uid, gid) |
| 710 | |
| 711 | 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] | 712 | 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] | 713 | :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] | 714 | gid)``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 715 | |
Christian Heimes | 4e30a84 | 2007-11-30 22:12:06 +0000 | [diff] [blame] | 716 | Availability: Unix. |
| 717 | |
| 718 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 719 | .. function:: fdatasync(fd) |
| 720 | |
| 721 | 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] | 722 | metadata. |
| 723 | |
| 724 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 725 | |
Benjamin Peterson | fa0d703 | 2009-06-01 22:42:33 +0000 | [diff] [blame] | 726 | .. note:: |
| 727 | This function is not available on MacOS. |
| 728 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 729 | |
| 730 | .. function:: fpathconf(fd, name) |
| 731 | |
| 732 | Return system configuration information relevant to an open file. *name* |
| 733 | specifies the configuration value to retrieve; it may be a string which is the |
| 734 | name of a defined system value; these names are specified in a number of |
| 735 | standards (POSIX.1, Unix 95, Unix 98, and others). Some platforms define |
| 736 | additional names as well. The names known to the host operating system are |
| 737 | given in the ``pathconf_names`` dictionary. For configuration variables not |
| 738 | included in that mapping, passing an integer for *name* is also accepted. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 739 | |
| 740 | If *name* is a string and is not known, :exc:`ValueError` is raised. If a |
| 741 | specific value for *name* is not supported by the host system, even if it is |
| 742 | included in ``pathconf_names``, an :exc:`OSError` is raised with |
| 743 | :const:`errno.EINVAL` for the error number. |
| 744 | |
Georg Brandl | 4d399a4 | 2012-06-25 07:40:32 +0200 | [diff] [blame] | 745 | 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] | 746 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 747 | Availability: Unix. |
| 748 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 749 | |
Victor Stinner | 4195b5c | 2012-02-08 23:03:19 +0100 | [diff] [blame] | 750 | .. function:: fstat(fd) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 751 | |
Georg Brandl | 4d399a4 | 2012-06-25 07:40:32 +0200 | [diff] [blame] | 752 | Return status for file descriptor *fd*, like :func:`~os.stat`. As of Python |
Georg Brandl | b9df00c | 2012-06-24 12:38:14 +0200 | [diff] [blame] | 753 | 3.3, this is equivalent to ``os.stat(fd)``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 754 | |
| 755 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 756 | |
Georg Brandl | b1a1ac0 | 2012-06-24 11:54:07 +0200 | [diff] [blame] | 757 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 758 | .. function:: fstatvfs(fd) |
| 759 | |
Georg Brandl | b9df00c | 2012-06-24 12:38:14 +0200 | [diff] [blame] | 760 | Return information about the filesystem containing the file associated with |
Georg Brandl | 4d399a4 | 2012-06-25 07:40:32 +0200 | [diff] [blame] | 761 | 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] | 762 | equivalent to ``os.statvfs(fd)``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 763 | |
| 764 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 765 | |
| 766 | |
| 767 | .. function:: fsync(fd) |
| 768 | |
| 769 | 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] | 770 | 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] | 771 | |
Antoine Pitrou | 11cb961 | 2010-09-15 11:11:28 +0000 | [diff] [blame] | 772 | If you're starting with a buffered Python :term:`file object` *f*, first do |
| 773 | ``f.flush()``, and then do ``os.fsync(f.fileno())``, to ensure that all internal |
| 774 | buffers associated with *f* are written to disk. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 775 | |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 776 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 777 | |
| 778 | |
| 779 | .. function:: ftruncate(fd, length) |
| 780 | |
Georg Brandl | 306336b | 2012-06-24 12:55:33 +0200 | [diff] [blame] | 781 | 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] | 782 | 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] | 783 | ``os.truncate(fd, length)``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 784 | |
| 785 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 786 | |
| 787 | |
| 788 | .. function:: isatty(fd) |
| 789 | |
| 790 | 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] | 791 | tty(-like) device, else ``False``. |
| 792 | |
| 793 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 794 | |
| 795 | |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 796 | .. function:: lockf(fd, cmd, len) |
| 797 | |
| 798 | Apply, test or remove a POSIX lock on an open file descriptor. |
| 799 | *fd* is an open file descriptor. |
| 800 | *cmd* specifies the command to use - one of :data:`F_LOCK`, :data:`F_TLOCK`, |
| 801 | :data:`F_ULOCK` or :data:`F_TEST`. |
| 802 | *len* specifies the section of the file to lock. |
| 803 | |
| 804 | Availability: Unix. |
| 805 | |
| 806 | .. versionadded:: 3.3 |
| 807 | |
| 808 | |
| 809 | .. data:: F_LOCK |
| 810 | F_TLOCK |
| 811 | F_ULOCK |
| 812 | F_TEST |
| 813 | |
| 814 | Flags that specify what action :func:`lockf` will take. |
| 815 | |
| 816 | Availability: Unix. |
| 817 | |
| 818 | .. versionadded:: 3.3 |
| 819 | |
Georg Brandl | f62445a | 2012-06-24 13:31:20 +0200 | [diff] [blame] | 820 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 821 | .. function:: lseek(fd, pos, how) |
| 822 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 823 | Set the current position of file descriptor *fd* to position *pos*, modified |
| 824 | by *how*: :const:`SEEK_SET` or ``0`` to set the position relative to the |
| 825 | beginning of the file; :const:`SEEK_CUR` or ``1`` to set it relative to the |
| 826 | current position; :const:`os.SEEK_END` or ``2`` to set it relative to the end of |
Victor Stinner | e83f899 | 2011-12-17 23:15:09 +0100 | [diff] [blame] | 827 | 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] | 828 | |
| 829 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 830 | |
| 831 | |
Georg Brandl | 8569e58 | 2010-05-19 20:57:08 +0000 | [diff] [blame] | 832 | .. data:: SEEK_SET |
| 833 | SEEK_CUR |
| 834 | SEEK_END |
| 835 | |
| 836 | 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] | 837 | respectively. |
| 838 | |
| 839 | Availability: Unix, Windows. |
Georg Brandl | 8569e58 | 2010-05-19 20:57:08 +0000 | [diff] [blame] | 840 | |
Jesus Cea | 9436361 | 2012-06-22 18:32:07 +0200 | [diff] [blame] | 841 | .. versionadded:: 3.3 |
| 842 | Some operating systems could support additional values, like |
| 843 | :data:`os.SEEK_HOLE` or :data:`os.SEEK_DATA`. |
| 844 | |
Georg Brandl | 8569e58 | 2010-05-19 20:57:08 +0000 | [diff] [blame] | 845 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 846 | .. function:: open(file, flags, mode=0o777, *, dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 847 | |
Georg Brandl | f4a4123 | 2008-05-26 17:55:52 +0000 | [diff] [blame] | 848 | Open the file *file* and set various flags according to *flags* and possibly |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 849 | its mode according to *mode*. When computing *mode*, the current umask value |
| 850 | is first masked out. Return the file descriptor for the newly opened file. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 851 | |
| 852 | For a description of the flag and mode values, see the C run-time documentation; |
| 853 | flag constants (like :const:`O_RDONLY` and :const:`O_WRONLY`) are defined in |
Georg Brandl | 8569e58 | 2010-05-19 20:57:08 +0000 | [diff] [blame] | 854 | this module too (see :ref:`open-constants`). In particular, on Windows adding |
| 855 | :const:`O_BINARY` is needed to open files in binary mode. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 856 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 857 | This function can support :ref:`paths relative to directory descriptors |
| 858 | <dir_fd>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 859 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 860 | Availability: Unix, Windows. |
| 861 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 862 | .. note:: |
| 863 | |
Georg Brandl | 502d9a5 | 2009-07-26 15:02:41 +0000 | [diff] [blame] | 864 | 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] | 865 | 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] | 866 | :meth:`~file.read` and :meth:`~file.write` methods (and many more). To |
Antoine Pitrou | 11cb961 | 2010-09-15 11:11:28 +0000 | [diff] [blame] | 867 | wrap a file descriptor in a file object, use :func:`fdopen`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 868 | |
Antoine Pitrou | f65132d | 2011-02-25 23:25:17 +0000 | [diff] [blame] | 869 | .. versionadded:: 3.3 |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 870 | The *dir_fd* argument. |
Antoine Pitrou | f65132d | 2011-02-25 23:25:17 +0000 | [diff] [blame] | 871 | |
| 872 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 873 | .. function:: openpty() |
| 874 | |
| 875 | .. index:: module: pty |
| 876 | |
| 877 | Open a new pseudo-terminal pair. Return a pair of file descriptors ``(master, |
| 878 | slave)`` for the pty and the tty, respectively. For a (slightly) more portable |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 879 | approach, use the :mod:`pty` module. |
| 880 | |
| 881 | Availability: some flavors of Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 882 | |
| 883 | |
| 884 | .. function:: pipe() |
| 885 | |
| 886 | Create a pipe. Return a pair of file descriptors ``(r, w)`` usable for reading |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 887 | and writing, respectively. |
| 888 | |
| 889 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 890 | |
| 891 | |
Charles-François Natali | 368f34b | 2011-06-06 19:49:47 +0200 | [diff] [blame] | 892 | .. function:: pipe2(flags) |
Charles-François Natali | daafdd5 | 2011-05-29 20:07:40 +0200 | [diff] [blame] | 893 | |
| 894 | Create a pipe with *flags* set atomically. |
Charles-François Natali | 368f34b | 2011-06-06 19:49:47 +0200 | [diff] [blame] | 895 | *flags* can be constructed by ORing together one or more of these values: |
| 896 | :data:`O_NONBLOCK`, :data:`O_CLOEXEC`. |
Charles-François Natali | daafdd5 | 2011-05-29 20:07:40 +0200 | [diff] [blame] | 897 | Return a pair of file descriptors ``(r, w)`` usable for reading and writing, |
| 898 | respectively. |
| 899 | |
| 900 | Availability: some flavors of Unix. |
| 901 | |
| 902 | .. versionadded:: 3.3 |
| 903 | |
| 904 | |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 905 | .. function:: posix_fallocate(fd, offset, len) |
| 906 | |
| 907 | Ensures that enough disk space is allocated for the file specified by *fd* |
| 908 | starting from *offset* and continuing for *len* bytes. |
| 909 | |
| 910 | Availability: Unix. |
| 911 | |
| 912 | .. versionadded:: 3.3 |
| 913 | |
| 914 | |
| 915 | .. function:: posix_fadvise(fd, offset, len, advice) |
| 916 | |
| 917 | Announces an intention to access data in a specific pattern thus allowing |
| 918 | the kernel to make optimizations. |
| 919 | The advice applies to the region of the file specified by *fd* starting at |
| 920 | *offset* and continuing for *len* bytes. |
| 921 | *advice* is one of :data:`POSIX_FADV_NORMAL`, :data:`POSIX_FADV_SEQUENTIAL`, |
| 922 | :data:`POSIX_FADV_RANDOM`, :data:`POSIX_FADV_NOREUSE`, |
| 923 | :data:`POSIX_FADV_WILLNEED` or :data:`POSIX_FADV_DONTNEED`. |
| 924 | |
| 925 | Availability: Unix. |
| 926 | |
| 927 | .. versionadded:: 3.3 |
| 928 | |
| 929 | |
| 930 | .. data:: POSIX_FADV_NORMAL |
| 931 | POSIX_FADV_SEQUENTIAL |
| 932 | POSIX_FADV_RANDOM |
| 933 | POSIX_FADV_NOREUSE |
| 934 | POSIX_FADV_WILLNEED |
| 935 | POSIX_FADV_DONTNEED |
| 936 | |
| 937 | Flags that can be used in *advice* in :func:`posix_fadvise` that specify |
| 938 | the access pattern that is likely to be used. |
| 939 | |
| 940 | Availability: Unix. |
| 941 | |
| 942 | .. versionadded:: 3.3 |
| 943 | |
| 944 | |
| 945 | .. function:: pread(fd, buffersize, offset) |
| 946 | |
| 947 | Read from a file descriptor, *fd*, at a position of *offset*. It will read up |
| 948 | to *buffersize* number of bytes. The file offset remains unchanged. |
| 949 | |
| 950 | Availability: Unix. |
| 951 | |
| 952 | .. versionadded:: 3.3 |
| 953 | |
| 954 | |
| 955 | .. function:: pwrite(fd, string, offset) |
| 956 | |
| 957 | Write *string* to a file descriptor, *fd*, from *offset*, leaving the file |
| 958 | offset unchanged. |
| 959 | |
| 960 | Availability: Unix. |
| 961 | |
| 962 | .. versionadded:: 3.3 |
| 963 | |
| 964 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 965 | .. function:: read(fd, n) |
| 966 | |
Georg Brandl | b90be69 | 2009-07-29 16:14:16 +0000 | [diff] [blame] | 967 | 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] | 968 | 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] | 969 | empty bytes object is returned. |
| 970 | |
| 971 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 972 | |
| 973 | .. note:: |
| 974 | |
| 975 | 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] | 976 | descriptor as returned by :func:`os.open` or :func:`pipe`. To read a |
| 977 | "file object" returned by the built-in function :func:`open` or by |
| 978 | :func:`popen` or :func:`fdopen`, or :data:`sys.stdin`, use its |
| 979 | :meth:`~file.read` or :meth:`~file.readline` methods. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 980 | |
| 981 | |
Giampaolo Rodolà | c9c2c8b | 2011-02-25 14:39:16 +0000 | [diff] [blame] | 982 | .. function:: sendfile(out, in, offset, nbytes) |
| 983 | sendfile(out, in, offset, nbytes, headers=None, trailers=None, flags=0) |
| 984 | |
| 985 | Copy *nbytes* bytes from file descriptor *in* to file descriptor *out* |
| 986 | starting at *offset*. |
| 987 | Return the number of bytes sent. When EOF is reached return 0. |
| 988 | |
| 989 | The first function notation is supported by all platforms that define |
| 990 | :func:`sendfile`. |
| 991 | |
| 992 | On Linux, if *offset* is given as ``None``, the bytes are read from the |
| 993 | current position of *in* and the position of *in* is updated. |
| 994 | |
| 995 | The second case may be used on Mac OS X and FreeBSD where *headers* and |
| 996 | *trailers* are arbitrary sequences of buffers that are written before and |
| 997 | after the data from *in* is written. It returns the same as the first case. |
| 998 | |
| 999 | On Mac OS X and FreeBSD, a value of 0 for *nbytes* specifies to send until |
| 1000 | the end of *in* is reached. |
| 1001 | |
| 1002 | On Solaris, *out* may be the file descriptor of a regular file or the file |
| 1003 | descriptor of a socket. On all other platforms, *out* must be the file |
| 1004 | descriptor of an open socket. |
| 1005 | |
| 1006 | Availability: Unix. |
| 1007 | |
| 1008 | .. versionadded:: 3.3 |
| 1009 | |
| 1010 | |
| 1011 | .. data:: SF_NODISKIO |
| 1012 | SF_MNOWAIT |
| 1013 | SF_SYNC |
| 1014 | |
| 1015 | Parameters to the :func:`sendfile` function, if the implementation supports |
| 1016 | them. |
| 1017 | |
| 1018 | Availability: Unix. |
| 1019 | |
| 1020 | .. versionadded:: 3.3 |
| 1021 | |
| 1022 | |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 1023 | .. function:: readv(fd, buffers) |
| 1024 | |
| 1025 | Read from a file descriptor into a number of writable buffers. *buffers* is |
| 1026 | an arbitrary sequence of writable buffers. Returns the total number of bytes |
| 1027 | read. |
| 1028 | |
| 1029 | Availability: Unix. |
| 1030 | |
| 1031 | .. versionadded:: 3.3 |
| 1032 | |
| 1033 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1034 | .. function:: tcgetpgrp(fd) |
| 1035 | |
| 1036 | 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] | 1037 | file descriptor as returned by :func:`os.open`). |
| 1038 | |
| 1039 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1040 | |
| 1041 | |
| 1042 | .. function:: tcsetpgrp(fd, pg) |
| 1043 | |
| 1044 | 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] | 1045 | descriptor as returned by :func:`os.open`) to *pg*. |
| 1046 | |
| 1047 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1048 | |
| 1049 | |
| 1050 | .. function:: ttyname(fd) |
| 1051 | |
| 1052 | Return a string which specifies the terminal device associated with |
Georg Brandl | 9afde1c | 2007-11-01 20:32:30 +0000 | [diff] [blame] | 1053 | 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] | 1054 | exception is raised. |
| 1055 | |
| 1056 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1057 | |
| 1058 | |
| 1059 | .. function:: write(fd, str) |
| 1060 | |
Georg Brandl | b90be69 | 2009-07-29 16:14:16 +0000 | [diff] [blame] | 1061 | 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] | 1062 | bytes actually written. |
| 1063 | |
| 1064 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1065 | |
| 1066 | .. note:: |
| 1067 | |
| 1068 | 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] | 1069 | 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] | 1070 | 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] | 1071 | :func:`fdopen`, or :data:`sys.stdout` or :data:`sys.stderr`, use its |
| 1072 | :meth:`~file.write` method. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1073 | |
Georg Brandl | 8569e58 | 2010-05-19 20:57:08 +0000 | [diff] [blame] | 1074 | |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 1075 | .. function:: writev(fd, buffers) |
| 1076 | |
Ezio Melotti | f106449 | 2011-10-19 11:06:26 +0300 | [diff] [blame] | 1077 | Write the contents of *buffers* to file descriptor *fd*, where *buffers* |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 1078 | is an arbitrary sequence of buffers. |
| 1079 | Returns the total number of bytes written. |
| 1080 | |
| 1081 | Availability: Unix. |
| 1082 | |
| 1083 | .. versionadded:: 3.3 |
| 1084 | |
| 1085 | |
Georg Brandl | 8569e58 | 2010-05-19 20:57:08 +0000 | [diff] [blame] | 1086 | .. _open-constants: |
| 1087 | |
| 1088 | ``open()`` flag constants |
| 1089 | ~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 1090 | |
Georg Brandl | af265f4 | 2008-12-07 15:06:20 +0000 | [diff] [blame] | 1091 | The following constants are options for the *flags* parameter to the |
Benjamin Peterson | fa0d703 | 2009-06-01 22:42:33 +0000 | [diff] [blame] | 1092 | :func:`~os.open` function. They can be combined using the bitwise OR operator |
Georg Brandl | af265f4 | 2008-12-07 15:06:20 +0000 | [diff] [blame] | 1093 | ``|``. Some of them are not available on all platforms. For descriptions of |
| 1094 | their availability and use, consult the :manpage:`open(2)` manual page on Unix |
Doug Hellmann | eb097fc | 2009-09-20 20:56:56 +0000 | [diff] [blame] | 1095 | or `the MSDN <http://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1096 | |
| 1097 | |
| 1098 | .. data:: O_RDONLY |
| 1099 | O_WRONLY |
| 1100 | O_RDWR |
| 1101 | O_APPEND |
| 1102 | O_CREAT |
| 1103 | O_EXCL |
| 1104 | O_TRUNC |
| 1105 | |
Georg Brandl | af265f4 | 2008-12-07 15:06:20 +0000 | [diff] [blame] | 1106 | These constants are available on Unix and Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1107 | |
| 1108 | |
| 1109 | .. data:: O_DSYNC |
| 1110 | O_RSYNC |
| 1111 | O_SYNC |
| 1112 | O_NDELAY |
| 1113 | O_NONBLOCK |
| 1114 | O_NOCTTY |
| 1115 | O_SHLOCK |
| 1116 | O_EXLOCK |
Charles-François Natali | 1e045b1 | 2011-05-22 20:42:32 +0200 | [diff] [blame] | 1117 | O_CLOEXEC |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1118 | |
Georg Brandl | af265f4 | 2008-12-07 15:06:20 +0000 | [diff] [blame] | 1119 | These constants are only available on Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1120 | |
Victor Stinner | e3455c0 | 2011-10-20 00:46:21 +0200 | [diff] [blame] | 1121 | .. versionchanged:: 3.3 |
| 1122 | Add :data:`O_CLOEXEC` constant. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1123 | |
| 1124 | .. data:: O_BINARY |
Guido van Rossum | 0d3fb8a | 2007-11-26 23:23:18 +0000 | [diff] [blame] | 1125 | O_NOINHERIT |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1126 | O_SHORT_LIVED |
| 1127 | O_TEMPORARY |
| 1128 | O_RANDOM |
| 1129 | O_SEQUENTIAL |
| 1130 | O_TEXT |
| 1131 | |
Georg Brandl | af265f4 | 2008-12-07 15:06:20 +0000 | [diff] [blame] | 1132 | These constants are only available on Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1133 | |
| 1134 | |
Alexandre Vassalotti | bee3253 | 2008-05-16 18:15:12 +0000 | [diff] [blame] | 1135 | .. data:: O_ASYNC |
| 1136 | O_DIRECT |
Guido van Rossum | 0d3fb8a | 2007-11-26 23:23:18 +0000 | [diff] [blame] | 1137 | O_DIRECTORY |
| 1138 | O_NOFOLLOW |
| 1139 | O_NOATIME |
| 1140 | |
Georg Brandl | af265f4 | 2008-12-07 15:06:20 +0000 | [diff] [blame] | 1141 | These constants are GNU extensions and not present if they are not defined by |
| 1142 | the C library. |
Guido van Rossum | 0d3fb8a | 2007-11-26 23:23:18 +0000 | [diff] [blame] | 1143 | |
| 1144 | |
Victor Stinner | 8b905bd | 2011-10-25 13:34:04 +0200 | [diff] [blame] | 1145 | .. data:: RTLD_LAZY |
| 1146 | RTLD_NOW |
| 1147 | RTLD_GLOBAL |
| 1148 | RTLD_LOCAL |
| 1149 | RTLD_NODELETE |
| 1150 | RTLD_NOLOAD |
| 1151 | RTLD_DEEPBIND |
| 1152 | |
| 1153 | See the Unix manual page :manpage:`dlopen(3)`. |
| 1154 | |
| 1155 | .. versionadded:: 3.3 |
| 1156 | |
| 1157 | |
Antoine Pitrou | bcf2b59 | 2012-02-08 23:28:36 +0100 | [diff] [blame] | 1158 | .. _terminal-size: |
| 1159 | |
| 1160 | Querying the size of a terminal |
| 1161 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 1162 | |
| 1163 | .. versionadded:: 3.3 |
| 1164 | |
| 1165 | .. function:: get_terminal_size(fd=STDOUT_FILENO) |
| 1166 | |
| 1167 | Return the size of the terminal window as ``(columns, lines)``, |
| 1168 | tuple of type :class:`terminal_size`. |
| 1169 | |
| 1170 | The optional argument ``fd`` (default ``STDOUT_FILENO``, or standard |
| 1171 | output) specifies which file descriptor should be queried. |
| 1172 | |
| 1173 | If the file descriptor is not connected to a terminal, an :exc:`OSError` |
| 1174 | is thrown. |
| 1175 | |
| 1176 | :func:`shutil.get_terminal_size` is the high-level function which |
| 1177 | should normally be used, ``os.get_terminal_size`` is the low-level |
| 1178 | implementation. |
| 1179 | |
| 1180 | Availability: Unix, Windows. |
| 1181 | |
Georg Brandl | 6cff9ff | 2012-06-24 14:05:40 +0200 | [diff] [blame] | 1182 | .. class:: terminal_size |
Antoine Pitrou | bcf2b59 | 2012-02-08 23:28:36 +0100 | [diff] [blame] | 1183 | |
Georg Brandl | 6cff9ff | 2012-06-24 14:05:40 +0200 | [diff] [blame] | 1184 | A subclass of tuple, holding ``(columns, lines)`` of the terminal window size. |
Antoine Pitrou | bcf2b59 | 2012-02-08 23:28:36 +0100 | [diff] [blame] | 1185 | |
| 1186 | .. attribute:: columns |
| 1187 | |
| 1188 | Width of the terminal window in characters. |
| 1189 | |
| 1190 | .. attribute:: lines |
| 1191 | |
| 1192 | Height of the terminal window in characters. |
| 1193 | |
| 1194 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1195 | .. _os-file-dir: |
| 1196 | |
| 1197 | Files and Directories |
| 1198 | --------------------- |
| 1199 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1200 | On some Unix platforms, many of these functions support one or more of these |
| 1201 | features: |
| 1202 | |
| 1203 | .. _path_fd: |
| 1204 | |
Larry Hastings | 77892dc | 2012-06-25 03:27:33 -0700 | [diff] [blame] | 1205 | * **specifying a file descriptor:** |
| 1206 | 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] | 1207 | 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] | 1208 | referred to by the descriptor. (For POSIX systems, Python will call the |
| 1209 | ``f...`` version of the function.) |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1210 | |
| 1211 | You can check whether or not *path* can be specified as a file descriptor on |
| 1212 | your platform using :data:`os.supports_fd`. If it is unavailable, using it |
| 1213 | will raise a :exc:`NotImplementedError`. |
| 1214 | |
| 1215 | If the function also supports *dir_fd* or *follow_symlinks* arguments, it is |
| 1216 | an error to specify one of those when supplying *path* as a file descriptor. |
| 1217 | |
| 1218 | .. _dir_fd: |
| 1219 | |
Larry Hastings | 77892dc | 2012-06-25 03:27:33 -0700 | [diff] [blame] | 1220 | * **paths relative to directory descriptors:** If *dir_fd* is not ``None``, it |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1221 | should be a file descriptor referring to a directory, and the path to operate |
| 1222 | 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] | 1223 | 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] | 1224 | the ``...at`` or ``f...at`` version of the function.) |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1225 | |
| 1226 | You can check whether or not *dir_fd* is supported on your platform using |
| 1227 | :data:`os.supports_dir_fd`. If it is unavailable, using it will raise a |
| 1228 | :exc:`NotImplementedError`. |
| 1229 | |
| 1230 | .. _follow_symlinks: |
| 1231 | |
Larry Hastings | 77892dc | 2012-06-25 03:27:33 -0700 | [diff] [blame] | 1232 | * **not following symlinks:** If *follow_symlinks* is |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1233 | ``False``, and the last element of the path to operate on is a symbolic link, |
| 1234 | 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] | 1235 | 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] | 1236 | the function.) |
| 1237 | |
| 1238 | You can check whether or not *follow_symlinks* is supported on your platform |
| 1239 | using :data:`os.supports_follow_symlinks`. If it is unavailable, using it |
| 1240 | will raise a :exc:`NotImplementedError`. |
| 1241 | |
| 1242 | |
| 1243 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1244 | .. 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] | 1245 | |
| 1246 | Use the real uid/gid to test for access to *path*. Note that most operations |
| 1247 | will use the effective uid/gid, therefore this routine can be used in a |
| 1248 | suid/sgid environment to test if the invoking user has the specified access to |
| 1249 | *path*. *mode* should be :const:`F_OK` to test the existence of *path*, or it |
| 1250 | can be the inclusive OR of one or more of :const:`R_OK`, :const:`W_OK`, and |
| 1251 | :const:`X_OK` to test permissions. Return :const:`True` if access is allowed, |
| 1252 | :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] | 1253 | information. |
| 1254 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1255 | This function can support specifying :ref:`paths relative to directory |
| 1256 | descriptors <dir_fd>` and :ref:`not following symlinks <follow_symlinks>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1257 | |
| 1258 | If *effective_ids* is ``True``, :func:`access` will perform its access |
| 1259 | checks using the effective uid/gid instead of the real uid/gid. |
| 1260 | *effective_ids* may not be supported on your platform; you can check whether |
| 1261 | or not it is available using :data:`os.supports_effective_ids`. If it is |
| 1262 | unavailable, using it will raise a :exc:`NotImplementedError`. |
| 1263 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1264 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1265 | |
| 1266 | .. note:: |
| 1267 | |
Georg Brandl | 502d9a5 | 2009-07-26 15:02:41 +0000 | [diff] [blame] | 1268 | Using :func:`access` to check if a user is authorized to e.g. open a file |
| 1269 | before actually doing so using :func:`open` creates a security hole, |
| 1270 | because the user might exploit the short time interval between checking |
Benjamin Peterson | 249b508 | 2011-05-20 11:41:13 -0500 | [diff] [blame] | 1271 | and opening the file to manipulate it. It's preferable to use :term:`EAFP` |
| 1272 | techniques. For example:: |
| 1273 | |
| 1274 | if os.access("myfile", os.R_OK): |
| 1275 | with open("myfile") as fp: |
| 1276 | return fp.read() |
| 1277 | return "some default data" |
| 1278 | |
| 1279 | is better written as:: |
| 1280 | |
| 1281 | try: |
| 1282 | fp = open("myfile") |
Antoine Pitrou | 62ab10a0 | 2011-10-12 20:10:51 +0200 | [diff] [blame] | 1283 | except PermissionError: |
| 1284 | return "some default data" |
Benjamin Peterson | 249b508 | 2011-05-20 11:41:13 -0500 | [diff] [blame] | 1285 | else: |
| 1286 | with fp: |
| 1287 | return fp.read() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1288 | |
| 1289 | .. note:: |
| 1290 | |
| 1291 | I/O operations may fail even when :func:`access` indicates that they would |
| 1292 | succeed, particularly for operations on network filesystems which may have |
| 1293 | permissions semantics beyond the usual POSIX permission-bit model. |
| 1294 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1295 | .. versionchanged:: 3.3 |
| 1296 | Added the *dir_fd*, *effective_ids*, and *follow_symlinks* parameters. |
| 1297 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1298 | |
| 1299 | .. data:: F_OK |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1300 | R_OK |
| 1301 | W_OK |
| 1302 | X_OK |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1303 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1304 | Values to pass as the *mode* parameter of :func:`access` to test the |
| 1305 | existence, readability, writability and executability of *path*, |
| 1306 | respectively. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1307 | |
| 1308 | |
| 1309 | .. function:: chdir(path) |
| 1310 | |
| 1311 | .. index:: single: directory; changing |
| 1312 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1313 | Change the current working directory to *path*. |
| 1314 | |
Larry Hastings | 77892dc | 2012-06-25 03:27:33 -0700 | [diff] [blame] | 1315 | This function can support :ref:`specifying a file descriptor <path_fd>`. The |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1316 | descriptor must refer to an opened directory, not an open file. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1317 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1318 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1319 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1320 | .. versionadded:: 3.3 |
| 1321 | Added support for specifying *path* as a file descriptor |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1322 | on some platforms. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1323 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1324 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1325 | .. function:: chflags(path, flags, *, follow_symlinks=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1326 | |
| 1327 | Set the flags of *path* to the numeric *flags*. *flags* may take a combination |
| 1328 | (bitwise OR) of the following values (as defined in the :mod:`stat` module): |
| 1329 | |
R David Murray | 3017806 | 2011-03-10 17:18:33 -0500 | [diff] [blame] | 1330 | * :data:`stat.UF_NODUMP` |
| 1331 | * :data:`stat.UF_IMMUTABLE` |
| 1332 | * :data:`stat.UF_APPEND` |
| 1333 | * :data:`stat.UF_OPAQUE` |
| 1334 | * :data:`stat.UF_NOUNLINK` |
Ned Deily | 3eb67d5 | 2011-06-28 00:00:28 -0700 | [diff] [blame] | 1335 | * :data:`stat.UF_COMPRESSED` |
| 1336 | * :data:`stat.UF_HIDDEN` |
R David Murray | 3017806 | 2011-03-10 17:18:33 -0500 | [diff] [blame] | 1337 | * :data:`stat.SF_ARCHIVED` |
| 1338 | * :data:`stat.SF_IMMUTABLE` |
| 1339 | * :data:`stat.SF_APPEND` |
| 1340 | * :data:`stat.SF_NOUNLINK` |
| 1341 | * :data:`stat.SF_SNAPSHOT` |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1342 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1343 | This function can support :ref:`not following symlinks <follow_symlinks>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1344 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 1345 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1346 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1347 | .. versionadded:: 3.3 |
| 1348 | The *follow_symlinks* argument. |
| 1349 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1350 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1351 | .. function:: chmod(path, mode, *, dir_fd=None, follow_symlinks=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1352 | |
| 1353 | 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] | 1354 | following values (as defined in the :mod:`stat` module) or bitwise ORed |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1355 | combinations of them: |
| 1356 | |
Alexandre Vassalotti | c22c6f2 | 2009-07-21 00:51:58 +0000 | [diff] [blame] | 1357 | * :data:`stat.S_ISUID` |
| 1358 | * :data:`stat.S_ISGID` |
| 1359 | * :data:`stat.S_ENFMT` |
| 1360 | * :data:`stat.S_ISVTX` |
| 1361 | * :data:`stat.S_IREAD` |
| 1362 | * :data:`stat.S_IWRITE` |
| 1363 | * :data:`stat.S_IEXEC` |
| 1364 | * :data:`stat.S_IRWXU` |
| 1365 | * :data:`stat.S_IRUSR` |
| 1366 | * :data:`stat.S_IWUSR` |
| 1367 | * :data:`stat.S_IXUSR` |
| 1368 | * :data:`stat.S_IRWXG` |
| 1369 | * :data:`stat.S_IRGRP` |
| 1370 | * :data:`stat.S_IWGRP` |
| 1371 | * :data:`stat.S_IXGRP` |
| 1372 | * :data:`stat.S_IRWXO` |
| 1373 | * :data:`stat.S_IROTH` |
| 1374 | * :data:`stat.S_IWOTH` |
| 1375 | * :data:`stat.S_IXOTH` |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1376 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1377 | This function can support :ref:`specifying a file descriptor <path_fd>`, |
| 1378 | :ref:`paths relative to directory descriptors <dir_fd>` and :ref:`not |
| 1379 | following symlinks <follow_symlinks>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1380 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 1381 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1382 | |
| 1383 | .. note:: |
| 1384 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1385 | Although Windows supports :func:`chmod`, you can only set the file's |
| 1386 | read-only flag with it (via the ``stat.S_IWRITE`` and ``stat.S_IREAD`` |
| 1387 | constants or a corresponding integer value). All other bits are ignored. |
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 an open file descriptor, |
| 1391 | and the *dir_fd* and *follow_symlinks* arguments. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1392 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1393 | |
| 1394 | .. function:: chown(path, uid, gid, *, dir_fd=None, follow_symlinks=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1395 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1396 | Change the owner and group id of *path* to the numeric *uid* and *gid*. To |
| 1397 | leave one of the ids unchanged, set it to -1. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1398 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1399 | This function can support :ref:`specifying a file descriptor <path_fd>`, |
| 1400 | :ref:`paths relative to directory descriptors <dir_fd>` and :ref:`not |
| 1401 | following symlinks <follow_symlinks>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1402 | |
Sandro Tosi | d902a14 | 2011-08-22 23:28:27 +0200 | [diff] [blame] | 1403 | See :func:`shutil.chown` for a higher-level function that accepts names in |
| 1404 | addition to numeric ids. |
| 1405 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1406 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1407 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1408 | .. versionadded:: 3.3 |
| 1409 | Added support for specifying an open file descriptor for *path*, |
| 1410 | and the *dir_fd* and *follow_symlinks* arguments. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1411 | |
Benjamin Peterson | 799bd80 | 2011-08-31 22:15:17 -0400 | [diff] [blame] | 1412 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1413 | .. function:: chroot(path) |
| 1414 | |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 1415 | Change the root directory of the current process to *path*. |
| 1416 | |
| 1417 | Availability: Unix. |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1418 | |
| 1419 | |
| 1420 | .. function:: fchdir(fd) |
| 1421 | |
| 1422 | Change the current working directory to the directory represented by the file |
| 1423 | descriptor *fd*. The descriptor must refer to an opened directory, not an |
Georg Brandl | 4d399a4 | 2012-06-25 07:40:32 +0200 | [diff] [blame] | 1424 | 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] | 1425 | |
| 1426 | Availability: Unix. |
| 1427 | |
| 1428 | |
| 1429 | .. function:: getcwd() |
| 1430 | |
| 1431 | Return a string representing the current working directory. |
| 1432 | |
| 1433 | Availability: Unix, Windows. |
| 1434 | |
| 1435 | |
| 1436 | .. function:: getcwdb() |
| 1437 | |
| 1438 | Return a bytestring representing the current working directory. |
| 1439 | |
| 1440 | Availability: Unix, Windows. |
| 1441 | |
| 1442 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1443 | .. function:: lchflags(path, flags) |
| 1444 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1445 | 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] | 1446 | 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] | 1447 | ``os.chflags(path, flags, follow_symlinks=False)``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1448 | |
| 1449 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1450 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1451 | |
Christian Heimes | 9385266 | 2007-12-01 12:22:32 +0000 | [diff] [blame] | 1452 | .. function:: lchmod(path, mode) |
| 1453 | |
| 1454 | 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] | 1455 | 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] | 1456 | 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] | 1457 | ``os.chmod(path, mode, follow_symlinks=False)``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1458 | |
| 1459 | Availability: Unix. |
Christian Heimes | 9385266 | 2007-12-01 12:22:32 +0000 | [diff] [blame] | 1460 | |
Christian Heimes | 9385266 | 2007-12-01 12:22:32 +0000 | [diff] [blame] | 1461 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1462 | .. function:: lchown(path, uid, gid) |
| 1463 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1464 | 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] | 1465 | 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] | 1466 | to ``os.chown(path, uid, gid, follow_symlinks=False)``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1467 | |
| 1468 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1469 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1470 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1471 | .. 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] | 1472 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1473 | Create a hard link pointing to *src* named *dst*. |
Benjamin Peterson | 799bd80 | 2011-08-31 22:15:17 -0400 | [diff] [blame] | 1474 | |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 1475 | This function can support specifying *src_dir_fd* and/or *dst_dir_fd* to |
| 1476 | supply :ref:`paths relative to directory descriptors <dir_fd>`, and :ref:`not |
| 1477 | following symlinks <follow_symlinks>`. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1478 | |
Brian Curtin | 1b9df39 | 2010-11-24 20:24:31 +0000 | [diff] [blame] | 1479 | Availability: Unix, Windows. |
| 1480 | |
| 1481 | .. versionchanged:: 3.2 |
| 1482 | Added Windows support. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1483 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1484 | .. versionadded:: 3.3 |
| 1485 | Added the *src_dir_fd*, *dst_dir_fd*, and *follow_symlinks* arguments. |
| 1486 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1487 | |
Martin v. Löwis | 9c71f90 | 2010-07-24 10:09:11 +0000 | [diff] [blame] | 1488 | .. function:: listdir(path='.') |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1489 | |
Benjamin Peterson | 4469d0c | 2008-11-30 22:46:23 +0000 | [diff] [blame] | 1490 | 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] | 1491 | *path*. The list is in arbitrary order, and does not include the special |
| 1492 | entries ``'.'`` and ``'..'`` even if they are present in the directory. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1493 | |
Larry Hastings | fdaea06 | 2012-06-25 04:42:23 -0700 | [diff] [blame] | 1494 | *path* may be either of type ``str`` or of type ``bytes``. If *path* |
| 1495 | is of type ``bytes``, the filenames returned will also be of type ``bytes``; |
| 1496 | in all other circumstances, they will be of type ``str``. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1497 | |
Larry Hastings | 77892dc | 2012-06-25 03:27:33 -0700 | [diff] [blame] | 1498 | This function can also support :ref:`specifying a file descriptor |
| 1499 | <path_fd>`; the file descriptor must refer to a directory. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1500 | |
Larry Hastings | fdaea06 | 2012-06-25 04:42:23 -0700 | [diff] [blame] | 1501 | .. note:: |
| 1502 | To encode ``str`` filenames to ``bytes``, use :func:`~os.fsencode`. |
| 1503 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1504 | Availability: Unix, Windows. |
| 1505 | |
Martin v. Löwis | c9e1c7d | 2010-07-23 12:16:41 +0000 | [diff] [blame] | 1506 | .. versionchanged:: 3.2 |
| 1507 | The *path* parameter became optional. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1508 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1509 | .. versionadded:: 3.3 |
| 1510 | Added support for specifying an open file descriptor for *path*. |
Benjamin Peterson | 799bd80 | 2011-08-31 22:15:17 -0400 | [diff] [blame] | 1511 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1512 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1513 | .. function:: lstat(path, *, dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1514 | |
R. David Murray | 7b1aae9 | 2011-01-24 19:34:58 +0000 | [diff] [blame] | 1515 | Perform the equivalent of an :c:func:`lstat` system call on the given path. |
| 1516 | Similar to :func:`~os.stat`, but does not follow symbolic links. On |
| 1517 | platforms that do not support symbolic links, this is an alias for |
Georg Brandl | 4d399a4 | 2012-06-25 07:40:32 +0200 | [diff] [blame] | 1518 | :func:`~os.stat`. As of Python 3.3, this is equivalent to ``os.stat(path, |
Georg Brandl | b9df00c | 2012-06-24 12:38:14 +0200 | [diff] [blame] | 1519 | dir_fd=dir_fd, follow_symlinks=False)``. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1520 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1521 | This function can also support :ref:`paths relative to directory descriptors |
| 1522 | <dir_fd>`. |
Brian Curtin | c739569 | 2010-07-09 15:15:09 +0000 | [diff] [blame] | 1523 | |
Georg Brandl | b382337 | 2010-07-10 08:58:37 +0000 | [diff] [blame] | 1524 | .. versionchanged:: 3.2 |
| 1525 | Added support for Windows 6.0 (Vista) symbolic links. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1526 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1527 | .. versionchanged:: 3.3 |
| 1528 | Added the *dir_fd* parameter. |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 1529 | |
| 1530 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1531 | .. function:: mkdir(path, mode=0o777, *, dir_fd=None) |
| 1532 | |
| 1533 | Create a directory named *path* with numeric mode *mode*. |
| 1534 | |
| 1535 | On some systems, *mode* is ignored. Where it is used, the current umask |
| 1536 | value is first masked out. If the directory already exists, :exc:`OSError` |
| 1537 | is raised. |
| 1538 | |
| 1539 | This function can also support :ref:`paths relative to directory descriptors |
| 1540 | <dir_fd>`. |
| 1541 | |
| 1542 | It is also possible to create temporary directories; see the |
| 1543 | :mod:`tempfile` module's :func:`tempfile.mkdtemp` function. |
| 1544 | |
| 1545 | Availability: Unix, Windows. |
| 1546 | |
| 1547 | .. versionadded:: 3.3 |
| 1548 | The *dir_fd* argument. |
| 1549 | |
| 1550 | |
| 1551 | .. function:: makedirs(path, mode=0o777, exist_ok=False) |
| 1552 | |
| 1553 | .. index:: |
| 1554 | single: directory; creating |
| 1555 | single: UNC paths; and os.makedirs() |
| 1556 | |
| 1557 | Recursive directory creation function. Like :func:`mkdir`, but makes all |
Hynek Schlawack | 0230b6a | 2012-10-07 18:04:38 +0200 | [diff] [blame] | 1558 | intermediate-level directories needed to contain the leaf directory. |
| 1559 | |
| 1560 | The default *mode* is ``0o777`` (octal). On some systems, *mode* is |
| 1561 | ignored. Where it is used, the current umask value is first masked out. |
| 1562 | |
| 1563 | If *exists_ok* is ``False`` (the default), an :exc:`OSError` is raised if |
| 1564 | the target directory already exists. If *exists_ok* is ``True`` an |
| 1565 | :exc:`OSError` is still raised if the umask-masked *mode* is different from |
| 1566 | the existing mode, on systems where the mode is used. :exc:`OSError` will |
| 1567 | also be raised if the directory creation fails. |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1568 | |
| 1569 | .. note:: |
| 1570 | |
| 1571 | :func:`makedirs` will become confused if the path elements to create |
Hynek Schlawack | 0230b6a | 2012-10-07 18:04:38 +0200 | [diff] [blame] | 1572 | include :data:`pardir` (eg. ".." on UNIX systems). |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1573 | |
| 1574 | This function handles UNC paths correctly. |
| 1575 | |
| 1576 | .. versionadded:: 3.2 |
| 1577 | The *exist_ok* parameter. |
| 1578 | |
| 1579 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1580 | .. function:: mkfifo(path, mode=0o666, *, dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1581 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1582 | Create a FIFO (a named pipe) named *path* with numeric mode *mode*. |
| 1583 | The current umask value is first masked out from the mode. |
| 1584 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1585 | This function can also support :ref:`paths relative to directory descriptors |
| 1586 | <dir_fd>`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1587 | |
| 1588 | FIFOs are pipes that can be accessed like regular files. FIFOs exist until they |
| 1589 | are deleted (for example with :func:`os.unlink`). Generally, FIFOs are used as |
| 1590 | rendezvous between "client" and "server" type processes: the server opens the |
| 1591 | FIFO for reading, and the client opens it for writing. Note that :func:`mkfifo` |
| 1592 | doesn't open the FIFO --- it just creates the rendezvous point. |
| 1593 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1594 | Availability: Unix. |
| 1595 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1596 | .. versionadded:: 3.3 |
| 1597 | The *dir_fd* argument. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1598 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1599 | |
| 1600 | .. function:: mknod(filename, mode=0o600, device=0, *, dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1601 | |
| 1602 | Create a filesystem node (file, device special file or named pipe) named |
Georg Brandl | 1824415 | 2009-09-02 20:34:52 +0000 | [diff] [blame] | 1603 | *filename*. *mode* specifies both the permissions to use and the type of node |
| 1604 | to be created, being combined (bitwise OR) with one of ``stat.S_IFREG``, |
| 1605 | ``stat.S_IFCHR``, ``stat.S_IFBLK``, and ``stat.S_IFIFO`` (those constants are |
| 1606 | available in :mod:`stat`). For ``stat.S_IFCHR`` and ``stat.S_IFBLK``, |
| 1607 | *device* defines the newly created device special file (probably using |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1608 | :func:`os.makedev`), otherwise it is ignored. |
| 1609 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1610 | This function can also support :ref:`paths relative to directory descriptors |
| 1611 | <dir_fd>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1612 | |
| 1613 | .. versionadded:: 3.3 |
| 1614 | The *dir_fd* argument. |
| 1615 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1616 | |
| 1617 | .. function:: major(device) |
| 1618 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 1619 | Extract the device major number from a raw device number (usually the |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 1620 | :attr:`st_dev` or :attr:`st_rdev` field from :c:type:`stat`). |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1621 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1622 | |
| 1623 | .. function:: minor(device) |
| 1624 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 1625 | Extract the device minor number from a raw device number (usually the |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 1626 | :attr:`st_dev` or :attr:`st_rdev` field from :c:type:`stat`). |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1627 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1628 | |
| 1629 | .. function:: makedev(major, minor) |
| 1630 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 1631 | Compose a raw device number from the major and minor device numbers. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1632 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1633 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1634 | .. function:: pathconf(path, name) |
| 1635 | |
| 1636 | Return system configuration information relevant to a named file. *name* |
| 1637 | specifies the configuration value to retrieve; it may be a string which is the |
| 1638 | name of a defined system value; these names are specified in a number of |
| 1639 | standards (POSIX.1, Unix 95, Unix 98, and others). Some platforms define |
| 1640 | additional names as well. The names known to the host operating system are |
| 1641 | given in the ``pathconf_names`` dictionary. For configuration variables not |
| 1642 | included in that mapping, passing an integer for *name* is also accepted. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1643 | |
| 1644 | If *name* is a string and is not known, :exc:`ValueError` is raised. If a |
| 1645 | specific value for *name* is not supported by the host system, even if it is |
| 1646 | included in ``pathconf_names``, an :exc:`OSError` is raised with |
| 1647 | :const:`errno.EINVAL` for the error number. |
| 1648 | |
Larry Hastings | 77892dc | 2012-06-25 03:27:33 -0700 | [diff] [blame] | 1649 | This function can support :ref:`specifying a file descriptor |
Georg Brandl | 306336b | 2012-06-24 12:55:33 +0200 | [diff] [blame] | 1650 | <path_fd>`. |
| 1651 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1652 | Availability: Unix. |
| 1653 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1654 | |
| 1655 | .. data:: pathconf_names |
| 1656 | |
| 1657 | Dictionary mapping names accepted by :func:`pathconf` and :func:`fpathconf` to |
| 1658 | 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] | 1659 | can be used to determine the set of names known to the system. |
| 1660 | |
| 1661 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1662 | |
| 1663 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1664 | .. function:: readlink(path, *, dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1665 | |
| 1666 | 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] | 1667 | result may be either an absolute or relative pathname; if it is relative, it |
| 1668 | may be converted to an absolute pathname using |
| 1669 | ``os.path.join(os.path.dirname(path), result)``. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1670 | |
Georg Brandl | 76e5538 | 2008-10-08 16:34:57 +0000 | [diff] [blame] | 1671 | If the *path* is a string object, the result will also be a string object, |
| 1672 | and the call may raise an UnicodeDecodeError. If the *path* is a bytes |
| 1673 | object, the result will be a bytes object. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1674 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1675 | This function can also support :ref:`paths relative to directory descriptors |
| 1676 | <dir_fd>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1677 | |
Brian Curtin | c739569 | 2010-07-09 15:15:09 +0000 | [diff] [blame] | 1678 | Availability: Unix, Windows |
| 1679 | |
Georg Brandl | b382337 | 2010-07-10 08:58:37 +0000 | [diff] [blame] | 1680 | .. versionchanged:: 3.2 |
| 1681 | Added support for Windows 6.0 (Vista) symbolic links. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1682 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1683 | .. versionadded:: 3.3 |
| 1684 | The *dir_fd* argument. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1685 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1686 | |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 1687 | .. function:: remove(path, *, dir_fd=None) |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1688 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1689 | Remove (delete) the file *path*. If *path* is a directory, :exc:`OSError` is |
| 1690 | raised. Use :func:`rmdir` to remove directories. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1691 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1692 | This function can support :ref:`paths relative to directory descriptors |
| 1693 | <dir_fd>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1694 | |
| 1695 | On Windows, attempting to remove a file that is in use causes an exception to |
| 1696 | be raised; on Unix, the directory entry is removed but the storage allocated |
| 1697 | 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] | 1698 | |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 1699 | This function is identical to :func:`unlink`. |
| 1700 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1701 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1702 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1703 | .. versionadded:: 3.3 |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 1704 | The *dir_fd* argument. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1705 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1706 | |
| 1707 | .. function:: removedirs(path) |
| 1708 | |
| 1709 | .. index:: single: directory; deleting |
| 1710 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 1711 | Remove directories recursively. Works like :func:`rmdir` except that, if the |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1712 | leaf directory is successfully removed, :func:`removedirs` tries to |
| 1713 | successively remove every parent directory mentioned in *path* until an error |
| 1714 | is raised (which is ignored, because it generally means that a parent directory |
| 1715 | is not empty). For example, ``os.removedirs('foo/bar/baz')`` will first remove |
| 1716 | the directory ``'foo/bar/baz'``, and then remove ``'foo/bar'`` and ``'foo'`` if |
| 1717 | they are empty. Raises :exc:`OSError` if the leaf directory could not be |
| 1718 | successfully removed. |
| 1719 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1720 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1721 | .. function:: rename(src, dst, *, src_dir_fd=None, dst_dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1722 | |
| 1723 | Rename the file or directory *src* to *dst*. If *dst* is a directory, |
| 1724 | :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] | 1725 | 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] | 1726 | Unix flavors if *src* and *dst* are on different filesystems. If successful, |
| 1727 | the renaming will be an atomic operation (this is a POSIX requirement). On |
| 1728 | 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] | 1729 | file. |
| 1730 | |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 1731 | This function can support specifying *src_dir_fd* and/or *dst_dir_fd* to |
| 1732 | supply :ref:`paths relative to directory descriptors <dir_fd>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1733 | |
Antoine Pitrou | f3b2d88 | 2012-01-30 22:08:52 +0100 | [diff] [blame] | 1734 | If you want cross-platform overwriting of the destination, use :func:`replace`. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1735 | |
| 1736 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1737 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1738 | .. versionadded:: 3.3 |
| 1739 | The *src_dir_fd* and *dst_dir_fd* arguments. |
| 1740 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1741 | |
| 1742 | .. function:: renames(old, new) |
| 1743 | |
| 1744 | Recursive directory or file renaming function. Works like :func:`rename`, except |
| 1745 | creation of any intermediate directories needed to make the new pathname good is |
| 1746 | attempted first. After the rename, directories corresponding to rightmost path |
| 1747 | segments of the old name will be pruned away using :func:`removedirs`. |
| 1748 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1749 | .. note:: |
| 1750 | |
| 1751 | This function can fail with the new directory structure made if you lack |
| 1752 | permissions needed to remove the leaf directory or file. |
| 1753 | |
| 1754 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1755 | .. function:: replace(src, dst, *, src_dir_fd=None, dst_dir_fd=None) |
Antoine Pitrou | f3b2d88 | 2012-01-30 22:08:52 +0100 | [diff] [blame] | 1756 | |
| 1757 | Rename the file or directory *src* to *dst*. If *dst* is a directory, |
| 1758 | :exc:`OSError` will be raised. If *dst* exists and is a file, it will |
| 1759 | be replaced silently if the user has permission. The operation may fail |
| 1760 | if *src* and *dst* are on different filesystems. If successful, |
| 1761 | the renaming will be an atomic operation (this is a POSIX requirement). |
| 1762 | |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 1763 | This function can support specifying *src_dir_fd* and/or *dst_dir_fd* to |
| 1764 | supply :ref:`paths relative to directory descriptors <dir_fd>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1765 | |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 1766 | Availability: Unix, Windows. |
Antoine Pitrou | f3b2d88 | 2012-01-30 22:08:52 +0100 | [diff] [blame] | 1767 | |
| 1768 | .. versionadded:: 3.3 |
| 1769 | |
| 1770 | |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 1771 | .. function:: rmdir(path, *, dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1772 | |
Georg Brandl | a6053b4 | 2009-09-01 08:11:14 +0000 | [diff] [blame] | 1773 | Remove (delete) the directory *path*. Only works when the directory is |
| 1774 | empty, otherwise, :exc:`OSError` is raised. In order to remove whole |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1775 | directory trees, :func:`shutil.rmtree` can be used. |
| 1776 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1777 | This function can support :ref:`paths relative to directory descriptors |
| 1778 | <dir_fd>`. |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 1779 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1780 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1781 | |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 1782 | .. versionadded:: 3.3 |
| 1783 | The *dir_fd* parameter. |
| 1784 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1785 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1786 | .. function:: stat(path, *, dir_fd=None, follow_symlinks=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1787 | |
R. David Murray | 7b1aae9 | 2011-01-24 19:34:58 +0000 | [diff] [blame] | 1788 | Perform the equivalent of a :c:func:`stat` system call on the given path. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1789 | *path* may be specified as either a string or as an open file descriptor. |
| 1790 | (This function normally follows symlinks; to stat a symlink add the argument |
| 1791 | ``follow_symlinks=False``, or use :func:`lstat`.) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1792 | |
Larry Hastings | 6fe20b3 | 2012-04-19 15:07:49 -0700 | [diff] [blame] | 1793 | The return value is an object whose attributes correspond roughly |
| 1794 | to the members of the :c:type:`stat` structure, namely: |
R. David Murray | 7b1aae9 | 2011-01-24 19:34:58 +0000 | [diff] [blame] | 1795 | |
| 1796 | * :attr:`st_mode` - protection bits, |
| 1797 | * :attr:`st_ino` - inode number, |
| 1798 | * :attr:`st_dev` - device, |
| 1799 | * :attr:`st_nlink` - number of hard links, |
| 1800 | * :attr:`st_uid` - user id of owner, |
| 1801 | * :attr:`st_gid` - group id of owner, |
| 1802 | * :attr:`st_size` - size of file, in bytes, |
Larry Hastings | 6fe20b3 | 2012-04-19 15:07:49 -0700 | [diff] [blame] | 1803 | * :attr:`st_atime` - time of most recent access expressed in seconds, |
| 1804 | * :attr:`st_mtime` - time of most recent content modification |
| 1805 | expressed in seconds, |
| 1806 | * :attr:`st_ctime` - platform dependent; time of most recent metadata |
| 1807 | change on Unix, or the time of creation on Windows, expressed in seconds |
| 1808 | * :attr:`st_atime_ns` - time of most recent access |
| 1809 | expressed in nanoseconds as an integer, |
| 1810 | * :attr:`st_mtime_ns` - time of most recent content modification |
| 1811 | expressed in nanoseconds as an integer, |
| 1812 | * :attr:`st_ctime_ns` - platform dependent; time of most recent metadata |
| 1813 | change on Unix, or the time of creation on Windows, |
| 1814 | expressed in nanoseconds as an integer |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1815 | |
| 1816 | On some Unix systems (such as Linux), the following attributes may also be |
R. David Murray | 7b1aae9 | 2011-01-24 19:34:58 +0000 | [diff] [blame] | 1817 | available: |
| 1818 | |
| 1819 | * :attr:`st_blocks` - number of blocks allocated for file |
| 1820 | * :attr:`st_blksize` - filesystem blocksize |
| 1821 | * :attr:`st_rdev` - type of device if an inode device |
| 1822 | * :attr:`st_flags` - user defined flags for file |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1823 | |
| 1824 | On other Unix systems (such as FreeBSD), the following attributes may be |
R. David Murray | 7b1aae9 | 2011-01-24 19:34:58 +0000 | [diff] [blame] | 1825 | available (but may be only filled out if root tries to use them): |
| 1826 | |
| 1827 | * :attr:`st_gen` - file generation number |
| 1828 | * :attr:`st_birthtime` - time of file creation |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1829 | |
| 1830 | On Mac OS systems, the following attributes may also be available: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1831 | |
R. David Murray | 7b1aae9 | 2011-01-24 19:34:58 +0000 | [diff] [blame] | 1832 | * :attr:`st_rsize` |
| 1833 | * :attr:`st_creator` |
| 1834 | * :attr:`st_type` |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1835 | |
| 1836 | .. note:: |
| 1837 | |
Senthil Kumaran | 3aac179 | 2011-07-04 11:43:51 -0700 | [diff] [blame] | 1838 | The exact meaning and resolution of the :attr:`st_atime`, |
Senthil Kumaran | a6bac95 | 2011-07-04 11:28:30 -0700 | [diff] [blame] | 1839 | :attr:`st_mtime`, and :attr:`st_ctime` attributes depend on the operating |
| 1840 | system and the file system. For example, on Windows systems using the FAT |
| 1841 | or FAT32 file systems, :attr:`st_mtime` has 2-second resolution, and |
| 1842 | :attr:`st_atime` has only 1-day resolution. See your operating system |
| 1843 | documentation for details. |
Larry Hastings | 6fe20b3 | 2012-04-19 15:07:49 -0700 | [diff] [blame] | 1844 | Similarly, although :attr:`st_atime_ns`, :attr:`st_mtime_ns`, |
| 1845 | and :attr:`st_ctime_ns` are always expressed in nanoseconds, many |
| 1846 | systems do not provide nanosecond precision. On systems that do |
| 1847 | provide nanosecond precision, the floating-point object used to |
| 1848 | store :attr:`st_atime`, :attr:`st_mtime`, and :attr:`st_ctime` |
| 1849 | cannot preserve all of it, and as such will be slightly inexact. |
| 1850 | If you need the exact timestamps you should always use |
| 1851 | :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] | 1852 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1853 | For backward compatibility, the return value of :func:`~os.stat` is also |
| 1854 | accessible as a tuple of at least 10 integers giving the most important (and |
| 1855 | portable) members of the :c:type:`stat` structure, in the order |
| 1856 | :attr:`st_mode`, :attr:`st_ino`, :attr:`st_dev`, :attr:`st_nlink`, |
| 1857 | :attr:`st_uid`, :attr:`st_gid`, :attr:`st_size`, :attr:`st_atime`, |
| 1858 | :attr:`st_mtime`, :attr:`st_ctime`. More items may be added at the end by |
| 1859 | some implementations. |
R. David Murray | 7b1aae9 | 2011-01-24 19:34:58 +0000 | [diff] [blame] | 1860 | |
R David Murray | ce478b9 | 2012-09-10 21:08:50 -0400 | [diff] [blame] | 1861 | This function can support :ref:`specifying a file descriptor <path_fd>` and |
| 1862 | :ref:`not following symlinks <follow_symlinks>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1863 | |
R. David Murray | 7b1aae9 | 2011-01-24 19:34:58 +0000 | [diff] [blame] | 1864 | .. index:: module: stat |
| 1865 | |
| 1866 | The standard module :mod:`stat` defines functions and constants that are useful |
| 1867 | for extracting information from a :c:type:`stat` structure. (On Windows, some |
| 1868 | items are filled with dummy values.) |
| 1869 | |
| 1870 | Example:: |
| 1871 | |
| 1872 | >>> import os |
| 1873 | >>> statinfo = os.stat('somefile.txt') |
| 1874 | >>> statinfo |
Raymond Hettinger | 8f0ae9a | 2011-02-18 00:53:55 +0000 | [diff] [blame] | 1875 | posix.stat_result(st_mode=33188, st_ino=7876932, st_dev=234881026, |
| 1876 | st_nlink=1, st_uid=501, st_gid=501, st_size=264, st_atime=1297230295, |
| 1877 | st_mtime=1297230027, st_ctime=1297230027) |
R. David Murray | 7b1aae9 | 2011-01-24 19:34:58 +0000 | [diff] [blame] | 1878 | >>> statinfo.st_size |
Raymond Hettinger | 8f0ae9a | 2011-02-18 00:53:55 +0000 | [diff] [blame] | 1879 | 264 |
R. David Murray | 7b1aae9 | 2011-01-24 19:34:58 +0000 | [diff] [blame] | 1880 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 1881 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1882 | |
Larry Hastings | 6fe20b3 | 2012-04-19 15:07:49 -0700 | [diff] [blame] | 1883 | .. versionadded:: 3.3 |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1884 | Added the *dir_fd* and *follow_symlinks* arguments, |
| 1885 | specifying a file descriptor instead of a path, |
| 1886 | and the :attr:`st_atime_ns`, :attr:`st_mtime_ns`, |
Larry Hastings | 6fe20b3 | 2012-04-19 15:07:49 -0700 | [diff] [blame] | 1887 | and :attr:`st_ctime_ns` members. |
| 1888 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1889 | |
| 1890 | .. function:: stat_float_times([newvalue]) |
| 1891 | |
| 1892 | Determine whether :class:`stat_result` represents time stamps as float objects. |
R. David Murray | 7b1aae9 | 2011-01-24 19:34:58 +0000 | [diff] [blame] | 1893 | 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] | 1894 | ``False``, future calls return ints. If *newvalue* is omitted, return the |
| 1895 | current setting. |
| 1896 | |
| 1897 | For compatibility with older Python versions, accessing :class:`stat_result` as |
| 1898 | a tuple always returns integers. |
| 1899 | |
Georg Brandl | 55ac8f0 | 2007-09-01 13:51:09 +0000 | [diff] [blame] | 1900 | Python now returns float values by default. Applications which do not work |
| 1901 | correctly with floating point time stamps can use this function to restore the |
| 1902 | old behaviour. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1903 | |
| 1904 | The resolution of the timestamps (that is the smallest possible fraction) |
| 1905 | depends on the system. Some systems only support second resolution; on these |
| 1906 | systems, the fraction will always be zero. |
| 1907 | |
| 1908 | It is recommended that this setting is only changed at program startup time in |
| 1909 | the *__main__* module; libraries should never change this setting. If an |
| 1910 | application uses a library that works incorrectly if floating point time stamps |
| 1911 | are processed, this application should turn the feature off until the library |
| 1912 | has been corrected. |
| 1913 | |
Victor Stinner | 034d0aa | 2012-06-05 01:22:15 +0200 | [diff] [blame] | 1914 | .. deprecated:: 3.3 |
| 1915 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1916 | |
| 1917 | .. function:: statvfs(path) |
| 1918 | |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 1919 | 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] | 1920 | an object whose attributes describe the filesystem on the given path, and |
Georg Brandl | 60203b4 | 2010-10-06 10:11:56 +0000 | [diff] [blame] | 1921 | correspond to the members of the :c:type:`statvfs` structure, namely: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1922 | :attr:`f_bsize`, :attr:`f_frsize`, :attr:`f_blocks`, :attr:`f_bfree`, |
| 1923 | :attr:`f_bavail`, :attr:`f_files`, :attr:`f_ffree`, :attr:`f_favail`, |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1924 | :attr:`f_flag`, :attr:`f_namemax`. |
| 1925 | |
Andrew M. Kuchling | 4ea04a3 | 2010-08-18 22:30:34 +0000 | [diff] [blame] | 1926 | Two module-level constants are defined for the :attr:`f_flag` attribute's |
| 1927 | bit-flags: if :const:`ST_RDONLY` is set, the filesystem is mounted |
| 1928 | read-only, and if :const:`ST_NOSUID` is set, the semantics of |
| 1929 | setuid/setgid bits are disabled or not supported. |
| 1930 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1931 | This function can support :ref:`specifying a file descriptor <path_fd>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1932 | |
Andrew M. Kuchling | 4ea04a3 | 2010-08-18 22:30:34 +0000 | [diff] [blame] | 1933 | .. versionchanged:: 3.2 |
| 1934 | The :const:`ST_RDONLY` and :const:`ST_NOSUID` constants were added. |
| 1935 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 1936 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1937 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1938 | .. versionadded:: 3.3 |
| 1939 | Added support for specifying an open file descriptor for *path*. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1940 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1941 | |
| 1942 | .. data:: supports_dir_fd |
| 1943 | |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 1944 | A :class:`~collections.Set` object indicating which functions in the |
| 1945 | :mod:`os` module permit use of their *dir_fd* parameter. Different platforms |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1946 | provide different functionality, and an option that might work on one might |
| 1947 | be unsupported on another. For consistency's sakes, functions that support |
| 1948 | *dir_fd* always allow specifying the parameter, but will throw an exception |
| 1949 | if the functionality is not actually available. |
| 1950 | |
| 1951 | To check whether a particular function permits use of its *dir_fd* |
| 1952 | parameter, use the ``in`` operator on ``supports_dir_fd``. As an example, |
| 1953 | this expression determines whether the *dir_fd* parameter of :func:`os.stat` |
| 1954 | is locally available:: |
| 1955 | |
| 1956 | os.stat in os.supports_dir_fd |
| 1957 | |
Georg Brandl | f62445a | 2012-06-24 13:31:20 +0200 | [diff] [blame] | 1958 | Currently *dir_fd* parameters only work on Unix platforms; none of them work |
| 1959 | on Windows. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1960 | |
| 1961 | .. versionadded:: 3.3 |
| 1962 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1963 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1964 | .. data:: supports_effective_ids |
| 1965 | |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 1966 | A :class:`~collections.Set` object indicating which functions in the |
| 1967 | :mod:`os` module permit use of the *effective_ids* parameter for |
| 1968 | :func:`os.access`. If the local platform supports it, the collection will |
| 1969 | contain :func:`os.access`, otherwise it will be empty. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1970 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1971 | To check whether you can use the *effective_ids* parameter for |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1972 | :func:`os.access`, use the ``in`` operator on ``supports_dir_fd``, like so:: |
| 1973 | |
| 1974 | os.access in os.supports_effective_ids |
| 1975 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 1976 | Currently *effective_ids* only works on Unix platforms; it does not work on |
| 1977 | Windows. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1978 | |
| 1979 | .. versionadded:: 3.3 |
| 1980 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 1981 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1982 | .. data:: supports_fd |
| 1983 | |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 1984 | A :class:`~collections.Set` object indicating which functions in the |
| 1985 | :mod:`os` module permit specifying their *path* parameter as an open file |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 1986 | descriptor. Different platforms provide different functionality, and an |
| 1987 | option that might work on one might be unsupported on another. For |
| 1988 | consistency's sakes, functions that support *fd* always allow specifying |
| 1989 | the parameter, but will throw an exception if the functionality is not |
| 1990 | actually available. |
| 1991 | |
| 1992 | To check whether a particular function permits specifying an open file |
| 1993 | descriptor for its *path* parameter, use the ``in`` operator on |
| 1994 | ``supports_fd``. As an example, this expression determines whether |
| 1995 | :func:`os.chdir` accepts open file descriptors when called on your local |
| 1996 | platform:: |
| 1997 | |
| 1998 | os.chdir in os.supports_fd |
| 1999 | |
| 2000 | .. versionadded:: 3.3 |
| 2001 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 2002 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2003 | .. data:: supports_follow_symlinks |
| 2004 | |
Georg Brandl | aceaf90 | 2012-06-25 08:33:56 +0200 | [diff] [blame] | 2005 | A :class:`~collections.Set` object indicating which functions in the |
| 2006 | :mod:`os` module permit use of their *follow_symlinks* parameter. Different |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2007 | platforms provide different functionality, and an option that might work on |
| 2008 | one might be unsupported on another. For consistency's sakes, functions that |
| 2009 | support *follow_symlinks* always allow specifying the parameter, but will |
| 2010 | throw an exception if the functionality is not actually available. |
| 2011 | |
| 2012 | To check whether a particular function permits use of its *follow_symlinks* |
| 2013 | parameter, use the ``in`` operator on ``supports_follow_symlinks``. As an |
| 2014 | example, this expression determines whether the *follow_symlinks* parameter |
| 2015 | of :func:`os.stat` is locally available:: |
| 2016 | |
| 2017 | os.stat in os.supports_follow_symlinks |
| 2018 | |
| 2019 | .. versionadded:: 3.3 |
| 2020 | |
Georg Brandl | 8ccadaa | 2012-06-24 12:50:06 +0200 | [diff] [blame] | 2021 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2022 | .. function:: symlink(source, link_name, target_is_directory=False, *, dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2023 | |
Brian Curtin | c739569 | 2010-07-09 15:15:09 +0000 | [diff] [blame] | 2024 | Create a symbolic link pointing to *source* named *link_name*. |
| 2025 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2026 | On Windows, a symlink represents either a file or a directory, and does not |
| 2027 | morph to the target dynamically. If *target_is_directory* is set to ``True``, |
| 2028 | the symlink will be created as a directory symlink, otherwise as a file symlink |
| 2029 | (the default). On non-Window platforms, *target_is_directory* is ignored. |
Brian Curtin | d40e6f7 | 2010-07-08 21:39:08 +0000 | [diff] [blame] | 2030 | |
Georg Brandl | 64a41ed | 2010-10-06 08:52:48 +0000 | [diff] [blame] | 2031 | Symbolic link support was introduced in Windows 6.0 (Vista). :func:`symlink` |
| 2032 | will raise a :exc:`NotImplementedError` on Windows versions earlier than 6.0. |
Brian Curtin | 52173d4 | 2010-12-02 18:29:18 +0000 | [diff] [blame] | 2033 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 2034 | This function can support :ref:`paths relative to directory descriptors |
| 2035 | <dir_fd>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2036 | |
Brian Curtin | 52173d4 | 2010-12-02 18:29:18 +0000 | [diff] [blame] | 2037 | .. note:: |
| 2038 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2039 | On Windows, the *SeCreateSymbolicLinkPrivilege* is required in order to |
| 2040 | successfully create symlinks. This privilege is not typically granted to |
| 2041 | regular users but is available to accounts which can escalate privileges |
| 2042 | to the administrator level. Either obtaining the privilege or running your |
Brian Curtin | 9624559 | 2010-12-28 17:08:22 +0000 | [diff] [blame] | 2043 | application as an administrator are ways to successfully create symlinks. |
| 2044 | |
Brian Curtin | 9624559 | 2010-12-28 17:08:22 +0000 | [diff] [blame] | 2045 | :exc:`OSError` is raised when the function is called by an unprivileged |
| 2046 | user. |
Brian Curtin | d40e6f7 | 2010-07-08 21:39:08 +0000 | [diff] [blame] | 2047 | |
Georg Brandl | 64a41ed | 2010-10-06 08:52:48 +0000 | [diff] [blame] | 2048 | Availability: Unix, Windows. |
Brian Curtin | c739569 | 2010-07-09 15:15:09 +0000 | [diff] [blame] | 2049 | |
Georg Brandl | b382337 | 2010-07-10 08:58:37 +0000 | [diff] [blame] | 2050 | .. versionchanged:: 3.2 |
| 2051 | Added support for Windows 6.0 (Vista) symbolic links. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2052 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2053 | .. versionadded:: 3.3 |
| 2054 | Added the *dir_fd* argument, and now allow *target_is_directory* |
| 2055 | on non-Windows platforms. |
| 2056 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2057 | |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 2058 | .. function:: sync() |
| 2059 | |
| 2060 | Force write of everything to disk. |
| 2061 | |
| 2062 | Availability: Unix. |
| 2063 | |
| 2064 | .. versionadded:: 3.3 |
| 2065 | |
| 2066 | |
| 2067 | .. function:: truncate(path, length) |
| 2068 | |
| 2069 | Truncate the file corresponding to *path*, so that it is at most |
| 2070 | *length* bytes in size. |
| 2071 | |
Georg Brandl | 306336b | 2012-06-24 12:55:33 +0200 | [diff] [blame] | 2072 | This function can support :ref:`specifying a file descriptor <path_fd>`. |
| 2073 | |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 2074 | Availability: Unix. |
| 2075 | |
| 2076 | .. versionadded:: 3.3 |
| 2077 | |
| 2078 | |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 2079 | .. function:: unlink(path, *, dir_fd=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2080 | |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 2081 | Remove (delete) the file *path*. This function is identical to |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 2082 | :func:`remove`; the ``unlink`` name is its traditional Unix |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2083 | name. Please see the documentation for :func:`remove` for |
| 2084 | further information. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2085 | |
| 2086 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2087 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2088 | .. versionadded:: 3.3 |
Larry Hastings | b698d8e | 2012-06-23 16:55:07 -0700 | [diff] [blame] | 2089 | The *dir_fd* parameter. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2090 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2091 | |
| 2092 | .. function:: utime(path, times=None, *, ns=None, dir_fd=None, follow_symlinks=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2093 | |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2094 | Set the access and modified times of the file specified by *path*. |
| 2095 | |
| 2096 | :func:`utime` takes two optional parameters, *times* and *ns*. |
| 2097 | These specify the times set on *path* and are used as follows: |
| 2098 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2099 | - If *ns* is not ``None``, |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2100 | it must be a 2-tuple of the form ``(atime_ns, mtime_ns)`` |
| 2101 | where each member is an int expressing nanoseconds. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2102 | - If *times* is not ``None``, |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2103 | it must be a 2-tuple of the form ``(atime, mtime)`` |
| 2104 | where each member is an int or float expressing seconds. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2105 | - If *times* and *ns* are both ``None``, |
| 2106 | this is equivalent to specifying ``ns=(atime_ns, mtime_ns)`` |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2107 | where both times are the current time. |
| 2108 | (The effect is similar to running the Unix program |
| 2109 | :program:`touch` on *path*.) |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2110 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2111 | It is an error to specify tuples for both *times* and *ns*. |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2112 | |
| 2113 | Whether a directory can be given for *path* |
Brian Curtin | 52fbea1 | 2011-11-06 13:41:17 -0600 | [diff] [blame] | 2114 | depends on whether the operating system implements directories as files |
| 2115 | (for example, Windows does not). Note that the exact times you set here may |
| 2116 | not be returned by a subsequent :func:`~os.stat` call, depending on the |
| 2117 | resolution with which your operating system records access and modification |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2118 | times; see :func:`~os.stat`. The best way to preserve exact times is to |
| 2119 | use the *st_atime_ns* and *st_mtime_ns* fields from the :func:`os.stat` |
| 2120 | result object with the *ns* parameter to `utime`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2121 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 2122 | This function can support :ref:`specifying a file descriptor <path_fd>`, |
| 2123 | :ref:`paths relative to directory descriptors <dir_fd>` and :ref:`not |
| 2124 | following symlinks <follow_symlinks>`. |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2125 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2126 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2127 | |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2128 | .. versionadded:: 3.3 |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2129 | Added support for specifying an open file descriptor for *path*, |
| 2130 | and the *dir_fd*, *follow_symlinks*, and *ns* parameters. |
Larry Hastings | 76ad59b | 2012-05-03 00:30:07 -0700 | [diff] [blame] | 2131 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2132 | |
Georg Brandl | 1824415 | 2009-09-02 20:34:52 +0000 | [diff] [blame] | 2133 | .. function:: walk(top, topdown=True, onerror=None, followlinks=False) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2134 | |
| 2135 | .. index:: |
| 2136 | single: directory; walking |
| 2137 | single: directory; traversal |
| 2138 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2139 | Generate the file names in a directory tree by walking the tree |
| 2140 | 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] | 2141 | *top* (including *top* itself), it yields a 3-tuple ``(dirpath, dirnames, |
| 2142 | filenames)``. |
| 2143 | |
| 2144 | *dirpath* is a string, the path to the directory. *dirnames* is a list of the |
| 2145 | names of the subdirectories in *dirpath* (excluding ``'.'`` and ``'..'``). |
| 2146 | *filenames* is a list of the names of the non-directory files in *dirpath*. |
| 2147 | Note that the names in the lists contain no path components. To get a full path |
| 2148 | (which begins with *top*) to a file or directory in *dirpath*, do |
| 2149 | ``os.path.join(dirpath, name)``. |
| 2150 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2151 | 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] | 2152 | directory is generated before the triples for any of its subdirectories |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2153 | (directories are generated top-down). If *topdown* is ``False``, the triple for a |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2154 | directory is generated after the triples for all of its subdirectories |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2155 | (directories are generated bottom-up). |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2156 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2157 | 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] | 2158 | (perhaps using :keyword:`del` or slice assignment), and :func:`walk` will only |
| 2159 | recurse into the subdirectories whose names remain in *dirnames*; this can be |
| 2160 | used to prune the search, impose a specific order of visiting, or even to inform |
| 2161 | :func:`walk` about directories the caller creates or renames before it resumes |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2162 | :func:`walk` again. Modifying *dirnames* when *topdown* is ``False`` is |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2163 | ineffective, because in bottom-up mode the directories in *dirnames* are |
| 2164 | generated before *dirpath* itself is generated. |
| 2165 | |
Ezio Melotti | 67494f2 | 2011-10-18 12:59:39 +0300 | [diff] [blame] | 2166 | By default, errors from the :func:`listdir` call are ignored. If optional |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2167 | argument *onerror* is specified, it should be a function; it will be called with |
| 2168 | one argument, an :exc:`OSError` instance. It can report the error to continue |
| 2169 | with the walk, or raise the exception to abort the walk. Note that the filename |
| 2170 | is available as the ``filename`` attribute of the exception object. |
| 2171 | |
| 2172 | 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] | 2173 | directories. Set *followlinks* to ``True`` to visit directories pointed to by |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2174 | symlinks, on systems that support them. |
| 2175 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2176 | .. note:: |
| 2177 | |
Georg Brandl | 50c4000 | 2012-06-24 11:45:20 +0200 | [diff] [blame] | 2178 | Be aware that setting *followlinks* to ``True`` can lead to infinite |
| 2179 | recursion if a link points to a parent directory of itself. :func:`walk` |
| 2180 | does not keep track of the directories it visited already. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2181 | |
| 2182 | .. note:: |
| 2183 | |
| 2184 | If you pass a relative pathname, don't change the current working directory |
| 2185 | between resumptions of :func:`walk`. :func:`walk` never changes the current |
| 2186 | directory, and assumes that its caller doesn't either. |
| 2187 | |
| 2188 | This example displays the number of bytes taken by non-directory files in each |
| 2189 | directory under the starting directory, except that it doesn't look under any |
| 2190 | CVS subdirectory:: |
| 2191 | |
| 2192 | import os |
| 2193 | from os.path import join, getsize |
| 2194 | for root, dirs, files in os.walk('python/Lib/email'): |
Georg Brandl | 6911e3c | 2007-09-04 07:15:32 +0000 | [diff] [blame] | 2195 | print(root, "consumes", end=" ") |
| 2196 | print(sum(getsize(join(root, name)) for name in files), end=" ") |
| 2197 | print("bytes in", len(files), "non-directory files") |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2198 | if 'CVS' in dirs: |
| 2199 | dirs.remove('CVS') # don't visit CVS directories |
| 2200 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2201 | In the next example, walking the tree bottom-up is essential: :func:`rmdir` |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2202 | doesn't allow deleting a directory before the directory is empty:: |
| 2203 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2204 | # Delete everything reachable from the directory named in "top", |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2205 | # assuming there are no symbolic links. |
| 2206 | # CAUTION: This is dangerous! For example, if top == '/', it |
| 2207 | # could delete all your disk files. |
| 2208 | import os |
| 2209 | for root, dirs, files in os.walk(top, topdown=False): |
| 2210 | for name in files: |
| 2211 | os.remove(os.path.join(root, name)) |
| 2212 | for name in dirs: |
| 2213 | os.rmdir(os.path.join(root, name)) |
| 2214 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2215 | |
Larry Hastings | b403806 | 2012-07-15 10:57:38 -0700 | [diff] [blame] | 2216 | .. 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] | 2217 | |
| 2218 | .. index:: |
| 2219 | single: directory; walking |
| 2220 | single: directory; traversal |
| 2221 | |
Eli Bendersky | d049d5c | 2012-02-11 09:52:29 +0200 | [diff] [blame] | 2222 | 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] | 2223 | ``(dirpath, dirnames, filenames, dirfd)``, and it supports ``dir_fd``. |
Charles-François Natali | 7372b06 | 2012-02-05 15:15:38 +0100 | [diff] [blame] | 2224 | |
| 2225 | *dirpath*, *dirnames* and *filenames* are identical to :func:`walk` output, |
| 2226 | and *dirfd* is a file descriptor referring to the directory *dirpath*. |
| 2227 | |
Larry Hastings | c48fe98 | 2012-06-25 04:49:05 -0700 | [diff] [blame] | 2228 | This function always supports :ref:`paths relative to directory descriptors |
Larry Hastings | b403806 | 2012-07-15 10:57:38 -0700 | [diff] [blame] | 2229 | <dir_fd>` and :ref:`not following symlinks <follow_symlinks>`. Note however |
Larry Hastings | 950b76a | 2012-07-15 17:32:36 -0700 | [diff] [blame] | 2230 | that, unlike other functions, the :func:`fwalk` default value for |
Larry Hastings | b403806 | 2012-07-15 10:57:38 -0700 | [diff] [blame] | 2231 | *follow_symlinks* is ``False``. |
Larry Hastings | c48fe98 | 2012-06-25 04:49:05 -0700 | [diff] [blame] | 2232 | |
Charles-François Natali | 7372b06 | 2012-02-05 15:15:38 +0100 | [diff] [blame] | 2233 | .. note:: |
| 2234 | |
| 2235 | Since :func:`fwalk` yields file descriptors, those are only valid until |
| 2236 | the next iteration step, so you should duplicate them (e.g. with |
| 2237 | :func:`dup`) if you want to keep them longer. |
| 2238 | |
| 2239 | This example displays the number of bytes taken by non-directory files in each |
| 2240 | directory under the starting directory, except that it doesn't look under any |
| 2241 | CVS subdirectory:: |
| 2242 | |
| 2243 | import os |
| 2244 | for root, dirs, files, rootfd in os.fwalk('python/Lib/email'): |
| 2245 | print(root, "consumes", end="") |
Hynek Schlawack | 1729b8f | 2012-06-24 16:11:08 +0200 | [diff] [blame] | 2246 | 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] | 2247 | end="") |
| 2248 | print("bytes in", len(files), "non-directory files") |
| 2249 | if 'CVS' in dirs: |
| 2250 | dirs.remove('CVS') # don't visit CVS directories |
| 2251 | |
| 2252 | In the next example, walking the tree bottom-up is essential: |
Victor Stinner | 69a6ca5 | 2012-08-05 15:18:02 +0200 | [diff] [blame] | 2253 | :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] | 2254 | empty:: |
| 2255 | |
| 2256 | # Delete everything reachable from the directory named in "top", |
| 2257 | # assuming there are no symbolic links. |
| 2258 | # CAUTION: This is dangerous! For example, if top == '/', it |
| 2259 | # could delete all your disk files. |
| 2260 | import os |
| 2261 | for root, dirs, files, rootfd in os.fwalk(top, topdown=False): |
| 2262 | for name in files: |
Victor Stinner | 69a6ca5 | 2012-08-05 15:18:02 +0200 | [diff] [blame] | 2263 | os.unlink(name, dir_fd=rootfd) |
Charles-François Natali | 7372b06 | 2012-02-05 15:15:38 +0100 | [diff] [blame] | 2264 | for name in dirs: |
Victor Stinner | 69a6ca5 | 2012-08-05 15:18:02 +0200 | [diff] [blame] | 2265 | os.rmdir(name, dir_fd=rootfd) |
Charles-François Natali | 7372b06 | 2012-02-05 15:15:38 +0100 | [diff] [blame] | 2266 | |
| 2267 | Availability: Unix. |
| 2268 | |
| 2269 | .. versionadded:: 3.3 |
| 2270 | |
| 2271 | |
Georg Brandl | b9831ab | 2012-06-24 11:57:07 +0200 | [diff] [blame] | 2272 | Linux extended attributes |
| 2273 | ~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 2274 | |
| 2275 | .. versionadded:: 3.3 |
| 2276 | |
| 2277 | These functions are all available on Linux only. |
| 2278 | |
| 2279 | .. function:: getxattr(path, attribute, *, follow_symlinks=True) |
| 2280 | |
| 2281 | Return the value of the extended filesystem attribute *attribute* for |
| 2282 | *path*. *attribute* can be bytes or str. If it is str, it is encoded |
| 2283 | with the filesystem encoding. |
| 2284 | |
| 2285 | This function can support :ref:`specifying a file descriptor <path_fd>` and |
| 2286 | :ref:`not following symlinks <follow_symlinks>`. |
| 2287 | |
| 2288 | |
| 2289 | .. function:: listxattr(path=None, *, follow_symlinks=True) |
| 2290 | |
| 2291 | Return a list of the extended filesystem attributes on *path*. The |
| 2292 | attributes in the list are represented as strings decoded with the filesystem |
| 2293 | encoding. If *path* is ``None``, :func:`listxattr` will examine the current |
| 2294 | directory. |
| 2295 | |
| 2296 | This function can support :ref:`specifying a file descriptor <path_fd>` and |
| 2297 | :ref:`not following symlinks <follow_symlinks>`. |
| 2298 | |
| 2299 | |
| 2300 | .. function:: removexattr(path, attribute, *, follow_symlinks=True) |
| 2301 | |
| 2302 | Removes the extended filesystem attribute *attribute* from *path*. |
| 2303 | *attribute* should be bytes or str. If it is a string, it is encoded |
| 2304 | with the filesystem encoding. |
| 2305 | |
| 2306 | This function can support :ref:`specifying a file descriptor <path_fd>` and |
| 2307 | :ref:`not following symlinks <follow_symlinks>`. |
| 2308 | |
| 2309 | |
| 2310 | .. function:: setxattr(path, attribute, value, flags=0, *, follow_symlinks=True) |
| 2311 | |
| 2312 | Set the extended filesystem attribute *attribute* on *path* to *value*. |
| 2313 | *attribute* must be a bytes or str with no embedded NULs. If it is a str, |
| 2314 | it is encoded with the filesystem encoding. *flags* may be |
| 2315 | :data:`XATTR_REPLACE` or :data:`XATTR_CREATE`. If :data:`XATTR_REPLACE` is |
| 2316 | given and the attribute does not exist, ``EEXISTS`` will be raised. |
| 2317 | If :data:`XATTR_CREATE` is given and the attribute already exists, the |
| 2318 | attribute will not be created and ``ENODATA`` will be raised. |
| 2319 | |
| 2320 | This function can support :ref:`specifying a file descriptor <path_fd>` and |
| 2321 | :ref:`not following symlinks <follow_symlinks>`. |
| 2322 | |
| 2323 | .. note:: |
| 2324 | |
| 2325 | A bug in Linux kernel versions less than 2.6.39 caused the flags argument |
| 2326 | to be ignored on some filesystems. |
| 2327 | |
| 2328 | |
| 2329 | .. data:: XATTR_SIZE_MAX |
| 2330 | |
| 2331 | The maximum size the value of an extended attribute can be. Currently, this |
| 2332 | is 64 kilobytes on Linux. |
| 2333 | |
| 2334 | |
| 2335 | .. data:: XATTR_CREATE |
| 2336 | |
| 2337 | This is a possible value for the flags argument in :func:`setxattr`. It |
| 2338 | indicates the operation must create an attribute. |
| 2339 | |
| 2340 | |
| 2341 | .. data:: XATTR_REPLACE |
| 2342 | |
| 2343 | This is a possible value for the flags argument in :func:`setxattr`. It |
| 2344 | indicates the operation must replace an existing attribute. |
| 2345 | |
| 2346 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2347 | .. _os-process: |
| 2348 | |
| 2349 | Process Management |
| 2350 | ------------------ |
| 2351 | |
| 2352 | These functions may be used to create and manage processes. |
| 2353 | |
| 2354 | The various :func:`exec\*` functions take a list of arguments for the new |
| 2355 | program loaded into the process. In each case, the first of these arguments is |
| 2356 | passed to the new program as its own name rather than as an argument a user may |
| 2357 | 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] | 2358 | 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] | 2359 | ['foo', 'bar'])`` will only print ``bar`` on standard output; ``foo`` will seem |
| 2360 | to be ignored. |
| 2361 | |
| 2362 | |
| 2363 | .. function:: abort() |
| 2364 | |
| 2365 | Generate a :const:`SIGABRT` signal to the current process. On Unix, the default |
| 2366 | 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] | 2367 | an exit code of ``3``. Be aware that calling this function will not call the |
| 2368 | Python signal handler registered for :const:`SIGABRT` with |
| 2369 | :func:`signal.signal`. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2370 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2371 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2372 | |
| 2373 | |
| 2374 | .. function:: execl(path, arg0, arg1, ...) |
| 2375 | execle(path, arg0, arg1, ..., env) |
| 2376 | execlp(file, arg0, arg1, ...) |
| 2377 | execlpe(file, arg0, arg1, ..., env) |
| 2378 | execv(path, args) |
| 2379 | execve(path, args, env) |
| 2380 | execvp(file, args) |
| 2381 | execvpe(file, args, env) |
| 2382 | |
| 2383 | These functions all execute a new program, replacing the current process; they |
| 2384 | 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] | 2385 | 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] | 2386 | :exc:`OSError` exceptions. |
Benjamin Peterson | e9bbc8b | 2008-09-28 02:06:32 +0000 | [diff] [blame] | 2387 | |
| 2388 | The current process is replaced immediately. Open file objects and |
| 2389 | descriptors are not flushed, so if there may be data buffered |
| 2390 | on these open files, you should flush them using |
| 2391 | :func:`sys.stdout.flush` or :func:`os.fsync` before calling an |
| 2392 | :func:`exec\*` function. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2393 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2394 | The "l" and "v" variants of the :func:`exec\*` functions differ in how |
| 2395 | command-line arguments are passed. The "l" variants are perhaps the easiest |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2396 | to work with if the number of parameters is fixed when the code is written; the |
| 2397 | individual parameters simply become additional parameters to the :func:`execl\*` |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2398 | functions. The "v" variants are good when the number of parameters is |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2399 | variable, with the arguments being passed in a list or tuple as the *args* |
| 2400 | parameter. In either case, the arguments to the child process should start with |
| 2401 | the name of the command being run, but this is not enforced. |
| 2402 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2403 | The variants which include a "p" near the end (:func:`execlp`, |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2404 | :func:`execlpe`, :func:`execvp`, and :func:`execvpe`) will use the |
| 2405 | :envvar:`PATH` environment variable to locate the program *file*. When the |
| 2406 | environment is being replaced (using one of the :func:`exec\*e` variants, |
| 2407 | discussed in the next paragraph), the new environment is used as the source of |
| 2408 | the :envvar:`PATH` variable. The other variants, :func:`execl`, :func:`execle`, |
| 2409 | :func:`execv`, and :func:`execve`, will not use the :envvar:`PATH` variable to |
| 2410 | locate the executable; *path* must contain an appropriate absolute or relative |
| 2411 | path. |
| 2412 | |
| 2413 | For :func:`execle`, :func:`execlpe`, :func:`execve`, and :func:`execvpe` (note |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2414 | 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] | 2415 | used to define the environment variables for the new process (these are used |
| 2416 | instead of the current process' environment); the functions :func:`execl`, |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2417 | :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] | 2418 | inherit the environment of the current process. |
Benjamin Peterson | e9bbc8b | 2008-09-28 02:06:32 +0000 | [diff] [blame] | 2419 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2420 | For :func:`execve` on some platforms, *path* may also be specified as an open |
| 2421 | file descriptor. This functionality may not be supported on your platform; |
| 2422 | you can check whether or not it is available using :data:`os.supports_fd`. |
| 2423 | If it is unavailable, using it will raise a :exc:`NotImplementedError`. |
| 2424 | |
Benjamin Peterson | e9bbc8b | 2008-09-28 02:06:32 +0000 | [diff] [blame] | 2425 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2426 | |
Larry Hastings | 9cf065c | 2012-06-22 16:30:09 -0700 | [diff] [blame] | 2427 | .. versionadded:: 3.3 |
| 2428 | Added support for specifying an open file descriptor for *path* |
| 2429 | for :func:`execve`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2430 | |
| 2431 | .. function:: _exit(n) |
| 2432 | |
Georg Brandl | 6f4e68d | 2010-10-17 10:51:45 +0000 | [diff] [blame] | 2433 | Exit the process with status *n*, without calling cleanup handlers, flushing |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2434 | stdio buffers, etc. |
| 2435 | |
| 2436 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2437 | |
| 2438 | .. note:: |
| 2439 | |
Georg Brandl | 6f4e68d | 2010-10-17 10:51:45 +0000 | [diff] [blame] | 2440 | The standard way to exit is ``sys.exit(n)``. :func:`_exit` should |
| 2441 | normally only be used in the child process after a :func:`fork`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2442 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2443 | 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] | 2444 | although they are not required. These are typically used for system programs |
| 2445 | written in Python, such as a mail server's external command delivery program. |
| 2446 | |
| 2447 | .. note:: |
| 2448 | |
| 2449 | Some of these may not be available on all Unix platforms, since there is some |
| 2450 | variation. These constants are defined where they are defined by the underlying |
| 2451 | platform. |
| 2452 | |
| 2453 | |
| 2454 | .. data:: EX_OK |
| 2455 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2456 | Exit code that means no error occurred. |
| 2457 | |
| 2458 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2459 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2460 | |
| 2461 | .. data:: EX_USAGE |
| 2462 | |
| 2463 | 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] | 2464 | number of arguments are given. |
| 2465 | |
| 2466 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2467 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2468 | |
| 2469 | .. data:: EX_DATAERR |
| 2470 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2471 | Exit code that means the input data was incorrect. |
| 2472 | |
| 2473 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2474 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2475 | |
| 2476 | .. data:: EX_NOINPUT |
| 2477 | |
| 2478 | 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] | 2479 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2480 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2481 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2482 | |
| 2483 | .. data:: EX_NOUSER |
| 2484 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2485 | Exit code that means a specified user did not exist. |
| 2486 | |
| 2487 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2488 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2489 | |
| 2490 | .. data:: EX_NOHOST |
| 2491 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2492 | Exit code that means a specified host did not exist. |
| 2493 | |
| 2494 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2495 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2496 | |
| 2497 | .. data:: EX_UNAVAILABLE |
| 2498 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2499 | Exit code that means that a required service is unavailable. |
| 2500 | |
| 2501 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2502 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2503 | |
| 2504 | .. data:: EX_SOFTWARE |
| 2505 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2506 | Exit code that means an internal software error was detected. |
| 2507 | |
| 2508 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2509 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2510 | |
| 2511 | .. data:: EX_OSERR |
| 2512 | |
| 2513 | 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] | 2514 | inability to fork or create a pipe. |
| 2515 | |
| 2516 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2517 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2518 | |
| 2519 | .. data:: EX_OSFILE |
| 2520 | |
| 2521 | 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] | 2522 | some other kind of error. |
| 2523 | |
| 2524 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2525 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2526 | |
| 2527 | .. data:: EX_CANTCREAT |
| 2528 | |
| 2529 | 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] | 2530 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2531 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2532 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2533 | |
| 2534 | .. data:: EX_IOERR |
| 2535 | |
| 2536 | 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] | 2537 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2538 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2539 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2540 | |
| 2541 | .. data:: EX_TEMPFAIL |
| 2542 | |
| 2543 | Exit code that means a temporary failure occurred. This indicates something |
| 2544 | 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] | 2545 | made during a retryable operation. |
| 2546 | |
| 2547 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2548 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2549 | |
| 2550 | .. data:: EX_PROTOCOL |
| 2551 | |
| 2552 | 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] | 2553 | understood. |
| 2554 | |
| 2555 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2556 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2557 | |
| 2558 | .. data:: EX_NOPERM |
| 2559 | |
| 2560 | Exit code that means that there were insufficient permissions to perform the |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2561 | operation (but not intended for file system problems). |
| 2562 | |
| 2563 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2564 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2565 | |
| 2566 | .. data:: EX_CONFIG |
| 2567 | |
| 2568 | Exit code that means that some kind of configuration error occurred. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2569 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2570 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2571 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2572 | |
| 2573 | .. data:: EX_NOTFOUND |
| 2574 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2575 | Exit code that means something like "an entry was not found". |
| 2576 | |
| 2577 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2578 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2579 | |
| 2580 | .. function:: fork() |
| 2581 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2582 | 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] | 2583 | parent. If an error occurs :exc:`OSError` is raised. |
Benjamin Peterson | bcd8ac3 | 2008-10-10 22:20:52 +0000 | [diff] [blame] | 2584 | |
| 2585 | Note that some platforms including FreeBSD <= 6.3, Cygwin and OS/2 EMX have |
| 2586 | known issues when using fork() from a thread. |
| 2587 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2588 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2589 | |
| 2590 | |
| 2591 | .. function:: forkpty() |
| 2592 | |
| 2593 | Fork a child process, using a new pseudo-terminal as the child's controlling |
| 2594 | terminal. Return a pair of ``(pid, fd)``, where *pid* is ``0`` in the child, the |
| 2595 | new child's process id in the parent, and *fd* is the file descriptor of the |
| 2596 | 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] | 2597 | :mod:`pty` module. If an error occurs :exc:`OSError` is raised. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2598 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2599 | Availability: some flavors of Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2600 | |
| 2601 | |
| 2602 | .. function:: kill(pid, sig) |
| 2603 | |
| 2604 | .. index:: |
| 2605 | single: process; killing |
| 2606 | single: process; signalling |
| 2607 | |
| 2608 | Send signal *sig* to the process *pid*. Constants for the specific signals |
| 2609 | available on the host platform are defined in the :mod:`signal` module. |
Brian Curtin | eb24d74 | 2010-04-12 17:16:38 +0000 | [diff] [blame] | 2610 | |
| 2611 | Windows: The :data:`signal.CTRL_C_EVENT` and |
| 2612 | :data:`signal.CTRL_BREAK_EVENT` signals are special signals which can |
| 2613 | only be sent to console processes which share a common console window, |
| 2614 | e.g., some subprocesses. Any other value for *sig* will cause the process |
| 2615 | to be unconditionally killed by the TerminateProcess API, and the exit code |
| 2616 | will be set to *sig*. The Windows version of :func:`kill` additionally takes |
| 2617 | process handles to be killed. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2618 | |
Victor Stinner | b3e7219 | 2011-05-08 01:46:11 +0200 | [diff] [blame] | 2619 | See also :func:`signal.pthread_kill`. |
| 2620 | |
Georg Brandl | 67b21b7 | 2010-08-17 15:07:14 +0000 | [diff] [blame] | 2621 | .. versionadded:: 3.2 |
| 2622 | Windows support. |
Brian Curtin | 904bd39 | 2010-04-20 15:28:06 +0000 | [diff] [blame] | 2623 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2624 | |
| 2625 | .. function:: killpg(pgid, sig) |
| 2626 | |
| 2627 | .. index:: |
| 2628 | single: process; killing |
| 2629 | single: process; signalling |
| 2630 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2631 | Send the signal *sig* to the process group *pgid*. |
| 2632 | |
| 2633 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2634 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2635 | |
| 2636 | .. function:: nice(increment) |
| 2637 | |
| 2638 | Add *increment* to the process's "niceness". Return the new niceness. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2639 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2640 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2641 | |
| 2642 | |
| 2643 | .. function:: plock(op) |
| 2644 | |
| 2645 | Lock program segments into memory. The value of *op* (defined in |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2646 | ``<sys/lock.h>``) determines which segments are locked. |
| 2647 | |
| 2648 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2649 | |
| 2650 | |
| 2651 | .. function:: popen(...) |
| 2652 | :noindex: |
| 2653 | |
| 2654 | Run child processes, returning opened pipes for communications. These functions |
| 2655 | are described in section :ref:`os-newstreams`. |
| 2656 | |
| 2657 | |
| 2658 | .. function:: spawnl(mode, path, ...) |
| 2659 | spawnle(mode, path, ..., env) |
| 2660 | spawnlp(mode, file, ...) |
| 2661 | spawnlpe(mode, file, ..., env) |
| 2662 | spawnv(mode, path, args) |
| 2663 | spawnve(mode, path, args, env) |
| 2664 | spawnvp(mode, file, args) |
| 2665 | spawnvpe(mode, file, args, env) |
| 2666 | |
| 2667 | Execute the program *path* in a new process. |
| 2668 | |
| 2669 | (Note that the :mod:`subprocess` module provides more powerful facilities for |
| 2670 | spawning new processes and retrieving their results; using that module is |
Benjamin Peterson | 87c8d87 | 2009-06-11 22:54:11 +0000 | [diff] [blame] | 2671 | preferable to using these functions. Check especially the |
| 2672 | :ref:`subprocess-replacements` section.) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2673 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2674 | 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] | 2675 | process; if *mode* is :const:`P_WAIT`, returns the process's exit code if it |
| 2676 | exits normally, or ``-signal``, where *signal* is the signal that killed the |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2677 | 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] | 2678 | be used with the :func:`waitpid` function. |
| 2679 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2680 | The "l" and "v" variants of the :func:`spawn\*` functions differ in how |
| 2681 | command-line arguments are passed. The "l" variants are perhaps the easiest |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2682 | to work with if the number of parameters is fixed when the code is written; the |
| 2683 | individual parameters simply become additional parameters to the |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2684 | :func:`spawnl\*` functions. The "v" variants are good when the number of |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2685 | parameters is variable, with the arguments being passed in a list or tuple as |
| 2686 | the *args* parameter. In either case, the arguments to the child process must |
| 2687 | start with the name of the command being run. |
| 2688 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2689 | The variants which include a second "p" near the end (:func:`spawnlp`, |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2690 | :func:`spawnlpe`, :func:`spawnvp`, and :func:`spawnvpe`) will use the |
| 2691 | :envvar:`PATH` environment variable to locate the program *file*. When the |
| 2692 | environment is being replaced (using one of the :func:`spawn\*e` variants, |
| 2693 | discussed in the next paragraph), the new environment is used as the source of |
| 2694 | the :envvar:`PATH` variable. The other variants, :func:`spawnl`, |
| 2695 | :func:`spawnle`, :func:`spawnv`, and :func:`spawnve`, will not use the |
| 2696 | :envvar:`PATH` variable to locate the executable; *path* must contain an |
| 2697 | appropriate absolute or relative path. |
| 2698 | |
| 2699 | For :func:`spawnle`, :func:`spawnlpe`, :func:`spawnve`, and :func:`spawnvpe` |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2700 | (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] | 2701 | which is used to define the environment variables for the new process (they are |
| 2702 | used instead of the current process' environment); the functions |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2703 | :func:`spawnl`, :func:`spawnlp`, :func:`spawnv`, and :func:`spawnvp` all cause |
Benjamin Peterson | d23f822 | 2009-04-05 19:13:16 +0000 | [diff] [blame] | 2704 | the new process to inherit the environment of the current process. Note that |
| 2705 | keys and values in the *env* dictionary must be strings; invalid keys or |
| 2706 | 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] | 2707 | |
| 2708 | As an example, the following calls to :func:`spawnlp` and :func:`spawnvpe` are |
| 2709 | equivalent:: |
| 2710 | |
| 2711 | import os |
| 2712 | os.spawnlp(os.P_WAIT, 'cp', 'cp', 'index.html', '/dev/null') |
| 2713 | |
| 2714 | L = ['cp', 'index.html', '/dev/null'] |
| 2715 | os.spawnvpe(os.P_WAIT, 'cp', L, os.environ) |
| 2716 | |
| 2717 | Availability: Unix, Windows. :func:`spawnlp`, :func:`spawnlpe`, :func:`spawnvp` |
Antoine Pitrou | 0e752dd | 2011-07-19 01:26:58 +0200 | [diff] [blame] | 2718 | and :func:`spawnvpe` are not available on Windows. :func:`spawnle` and |
| 2719 | :func:`spawnve` are not thread-safe on Windows; we advise you to use the |
| 2720 | :mod:`subprocess` module instead. |
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:: P_NOWAIT |
| 2724 | P_NOWAITO |
| 2725 | |
| 2726 | Possible values for the *mode* parameter to the :func:`spawn\*` family of |
| 2727 | functions. If either of these values is given, the :func:`spawn\*` functions |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2728 | 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] | 2729 | the return value. |
| 2730 | |
| 2731 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2732 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2733 | |
| 2734 | .. data:: P_WAIT |
| 2735 | |
| 2736 | Possible value for the *mode* parameter to the :func:`spawn\*` family of |
| 2737 | functions. If this is given as *mode*, the :func:`spawn\*` functions will not |
| 2738 | return until the new process has run to completion and will return the exit code |
| 2739 | 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] | 2740 | process. |
| 2741 | |
| 2742 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2743 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2744 | |
| 2745 | .. data:: P_DETACH |
| 2746 | P_OVERLAY |
| 2747 | |
| 2748 | Possible values for the *mode* parameter to the :func:`spawn\*` family of |
| 2749 | functions. These are less portable than those listed above. :const:`P_DETACH` |
| 2750 | is similar to :const:`P_NOWAIT`, but the new process is detached from the |
| 2751 | console of the calling process. If :const:`P_OVERLAY` is used, the current |
| 2752 | process will be replaced; the :func:`spawn\*` function will not return. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2753 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2754 | Availability: Windows. |
| 2755 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2756 | |
| 2757 | .. function:: startfile(path[, operation]) |
| 2758 | |
| 2759 | Start a file with its associated application. |
| 2760 | |
| 2761 | When *operation* is not specified or ``'open'``, this acts like double-clicking |
| 2762 | the file in Windows Explorer, or giving the file name as an argument to the |
| 2763 | :program:`start` command from the interactive command shell: the file is opened |
| 2764 | with whatever application (if any) its extension is associated. |
| 2765 | |
| 2766 | When another *operation* is given, it must be a "command verb" that specifies |
| 2767 | what should be done with the file. Common verbs documented by Microsoft are |
| 2768 | ``'print'`` and ``'edit'`` (to be used on files) as well as ``'explore'`` and |
| 2769 | ``'find'`` (to be used on directories). |
| 2770 | |
| 2771 | :func:`startfile` returns as soon as the associated application is launched. |
| 2772 | There is no option to wait for the application to close, and no way to retrieve |
| 2773 | the application's exit status. The *path* parameter is relative to the current |
| 2774 | 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] | 2775 | is not a slash (``'/'``); the underlying Win32 :c:func:`ShellExecute` function |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2776 | 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] | 2777 | the path is properly encoded for Win32. |
| 2778 | |
| 2779 | Availability: Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2780 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2781 | |
| 2782 | .. function:: system(command) |
| 2783 | |
| 2784 | 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] | 2785 | the Standard C function :c:func:`system`, and has the same limitations. |
Georg Brandl | 8f7b427 | 2010-10-14 06:35:53 +0000 | [diff] [blame] | 2786 | Changes to :data:`sys.stdin`, etc. are not reflected in the environment of |
| 2787 | the executed command. If *command* generates any output, it will be sent to |
| 2788 | the interpreter standard output stream. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2789 | |
| 2790 | 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] | 2791 | format specified for :func:`wait`. Note that POSIX does not specify the |
| 2792 | meaning of the return value of the C :c:func:`system` function, so the return |
| 2793 | value of the Python function is system-dependent. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2794 | |
Georg Brandl | 8f7b427 | 2010-10-14 06:35:53 +0000 | [diff] [blame] | 2795 | On Windows, the return value is that returned by the system shell after |
| 2796 | running *command*. The shell is given by the Windows environment variable |
| 2797 | :envvar:`COMSPEC`: it is usually :program:`cmd.exe`, which returns the exit |
| 2798 | status of the command run; on systems using a non-native shell, consult your |
| 2799 | shell documentation. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2800 | |
Georg Brandl | 8f7b427 | 2010-10-14 06:35:53 +0000 | [diff] [blame] | 2801 | The :mod:`subprocess` module provides more powerful facilities for spawning |
| 2802 | new processes and retrieving their results; using that module is preferable |
| 2803 | to using this function. See the :ref:`subprocess-replacements` section in |
| 2804 | the :mod:`subprocess` documentation for some helpful recipes. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2805 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2806 | Availability: Unix, Windows. |
| 2807 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2808 | |
| 2809 | .. function:: times() |
| 2810 | |
Larry Hastings | 605a62d | 2012-06-24 04:33:36 -0700 | [diff] [blame] | 2811 | Returns the current global process times. |
| 2812 | The return value is an object with five attributes: |
| 2813 | |
| 2814 | * :attr:`user` - user time |
| 2815 | * :attr:`system` - system time |
| 2816 | * :attr:`children_user` - user time of all child processes |
| 2817 | * :attr:`children_system` - system time of all child processes |
| 2818 | * :attr:`elapsed` - elapsed real time since a fixed point in the past |
| 2819 | |
| 2820 | For backwards compatibility, this object also behaves like a five-tuple |
| 2821 | containing :attr:`user`, :attr:`system`, :attr:`children_user`, |
| 2822 | :attr:`children_system`, and :attr:`elapsed` in that order. |
| 2823 | |
| 2824 | See the Unix manual page |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2825 | :manpage:`times(2)` or the corresponding Windows Platform API documentation. |
Larry Hastings | 605a62d | 2012-06-24 04:33:36 -0700 | [diff] [blame] | 2826 | On Windows, only :attr:`user` and :attr:`system` are known; the other |
| 2827 | attributes are zero. |
| 2828 | On OS/2, only :attr:`elapsed` is known; the other attributes are zero. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2829 | |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 2830 | Availability: Unix, Windows. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2831 | |
Larry Hastings | 605a62d | 2012-06-24 04:33:36 -0700 | [diff] [blame] | 2832 | .. versionchanged:: 3.3 |
| 2833 | Return type changed from a tuple to a tuple-like object |
| 2834 | with named attributes. |
| 2835 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2836 | |
| 2837 | .. function:: wait() |
| 2838 | |
| 2839 | Wait for completion of a child process, and return a tuple containing its pid |
| 2840 | and exit status indication: a 16-bit number, whose low byte is the signal number |
| 2841 | that killed the process, and whose high byte is the exit status (if the signal |
| 2842 | 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] | 2843 | produced. |
| 2844 | |
| 2845 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2846 | |
Ross Lagerwall | 7807c35 | 2011-03-17 20:20:30 +0200 | [diff] [blame] | 2847 | .. function:: waitid(idtype, id, options) |
| 2848 | |
| 2849 | Wait for the completion of one or more child processes. |
| 2850 | *idtype* can be :data:`P_PID`, :data:`P_PGID` or :data:`P_ALL`. |
| 2851 | *id* specifies the pid to wait on. |
| 2852 | *options* is constructed from the ORing of one or more of :data:`WEXITED`, |
| 2853 | :data:`WSTOPPED` or :data:`WCONTINUED` and additionally may be ORed with |
| 2854 | :data:`WNOHANG` or :data:`WNOWAIT`. The return value is an object |
| 2855 | representing the data contained in the :c:type:`siginfo_t` structure, namely: |
| 2856 | :attr:`si_pid`, :attr:`si_uid`, :attr:`si_signo`, :attr:`si_status`, |
| 2857 | :attr:`si_code` or ``None`` if :data:`WNOHANG` is specified and there are no |
| 2858 | children in a waitable state. |
| 2859 | |
| 2860 | Availability: Unix. |
| 2861 | |
| 2862 | .. versionadded:: 3.3 |
| 2863 | |
| 2864 | .. data:: P_PID |
| 2865 | P_PGID |
| 2866 | P_ALL |
| 2867 | |
| 2868 | These are the possible values for *idtype* in :func:`waitid`. They affect |
| 2869 | how *id* is interpreted. |
| 2870 | |
| 2871 | Availability: Unix. |
| 2872 | |
| 2873 | .. versionadded:: 3.3 |
| 2874 | |
| 2875 | .. data:: WEXITED |
| 2876 | WSTOPPED |
| 2877 | WNOWAIT |
| 2878 | |
| 2879 | Flags that can be used in *options* in :func:`waitid` that specify what |
| 2880 | child signal to wait for. |
| 2881 | |
| 2882 | Availability: Unix. |
| 2883 | |
| 2884 | .. versionadded:: 3.3 |
| 2885 | |
| 2886 | |
| 2887 | .. data:: CLD_EXITED |
| 2888 | CLD_DUMPED |
| 2889 | CLD_TRAPPED |
| 2890 | CLD_CONTINUED |
| 2891 | |
| 2892 | These are the possible values for :attr:`si_code` in the result returned by |
| 2893 | :func:`waitid`. |
| 2894 | |
| 2895 | Availability: Unix. |
| 2896 | |
| 2897 | .. versionadded:: 3.3 |
| 2898 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2899 | |
| 2900 | .. function:: waitpid(pid, options) |
| 2901 | |
| 2902 | The details of this function differ on Unix and Windows. |
| 2903 | |
| 2904 | On Unix: Wait for completion of a child process given by process id *pid*, and |
| 2905 | return a tuple containing its process id and exit status indication (encoded as |
| 2906 | for :func:`wait`). The semantics of the call are affected by the value of the |
| 2907 | integer *options*, which should be ``0`` for normal operation. |
| 2908 | |
| 2909 | If *pid* is greater than ``0``, :func:`waitpid` requests status information for |
| 2910 | that specific process. If *pid* is ``0``, the request is for the status of any |
| 2911 | child in the process group of the current process. If *pid* is ``-1``, the |
| 2912 | request pertains to any child of the current process. If *pid* is less than |
| 2913 | ``-1``, status is requested for any process in the process group ``-pid`` (the |
| 2914 | absolute value of *pid*). |
| 2915 | |
Benjamin Peterson | 4cd6a95 | 2008-08-17 20:23:46 +0000 | [diff] [blame] | 2916 | An :exc:`OSError` is raised with the value of errno when the syscall |
| 2917 | returns -1. |
| 2918 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2919 | On Windows: Wait for completion of a process given by process handle *pid*, and |
| 2920 | return a tuple containing *pid*, and its exit status shifted left by 8 bits |
| 2921 | (shifting makes cross-platform use of the function easier). A *pid* less than or |
| 2922 | equal to ``0`` has no special meaning on Windows, and raises an exception. The |
| 2923 | value of integer *options* has no effect. *pid* can refer to any process whose |
| 2924 | id is known, not necessarily a child process. The :func:`spawn` functions called |
| 2925 | with :const:`P_NOWAIT` return suitable process handles. |
| 2926 | |
| 2927 | |
Victor Stinner | 4195b5c | 2012-02-08 23:03:19 +0100 | [diff] [blame] | 2928 | .. function:: wait3([options]) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2929 | |
| 2930 | Similar to :func:`waitpid`, except no process id argument is given and a |
| 2931 | 3-element tuple containing the child's process id, exit status indication, and |
| 2932 | resource usage information is returned. Refer to :mod:`resource`.\ |
| 2933 | :func:`getrusage` for details on resource usage information. The option |
| 2934 | argument is the same as that provided to :func:`waitpid` and :func:`wait4`. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2935 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2936 | Availability: Unix. |
| 2937 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2938 | |
Victor Stinner | 4195b5c | 2012-02-08 23:03:19 +0100 | [diff] [blame] | 2939 | .. function:: wait4(pid, options) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2940 | |
| 2941 | Similar to :func:`waitpid`, except a 3-element tuple, containing the child's |
| 2942 | process id, exit status indication, and resource usage information is returned. |
| 2943 | Refer to :mod:`resource`.\ :func:`getrusage` for details on resource usage |
| 2944 | information. The arguments to :func:`wait4` are the same as those provided to |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2945 | :func:`waitpid`. |
| 2946 | |
| 2947 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2948 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2949 | |
| 2950 | .. data:: WNOHANG |
| 2951 | |
| 2952 | The option for :func:`waitpid` to return immediately if no child process status |
| 2953 | is available immediately. The function returns ``(0, 0)`` in this case. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2954 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 2955 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2956 | |
| 2957 | |
| 2958 | .. data:: WCONTINUED |
| 2959 | |
| 2960 | 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] | 2961 | from a job control stop since their status was last reported. |
| 2962 | |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 2963 | Availability: some Unix systems. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2964 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2965 | |
| 2966 | .. data:: WUNTRACED |
| 2967 | |
| 2968 | 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] | 2969 | their current state has not been reported since they were stopped. |
| 2970 | |
| 2971 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2972 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2973 | |
| 2974 | The following functions take a process status code as returned by |
| 2975 | :func:`system`, :func:`wait`, or :func:`waitpid` as a parameter. They may be |
| 2976 | used to determine the disposition of a process. |
| 2977 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2978 | .. function:: WCOREDUMP(status) |
| 2979 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2980 | Return ``True`` if a core dump was generated for the process, otherwise |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2981 | return ``False``. |
| 2982 | |
| 2983 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2984 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2985 | |
| 2986 | .. function:: WIFCONTINUED(status) |
| 2987 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2988 | 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] | 2989 | otherwise return ``False``. |
| 2990 | |
| 2991 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2992 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 2993 | |
| 2994 | .. function:: WIFSTOPPED(status) |
| 2995 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 2996 | Return ``True`` if the process has been stopped, otherwise return |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 2997 | ``False``. |
| 2998 | |
| 2999 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3000 | |
| 3001 | |
| 3002 | .. function:: WIFSIGNALED(status) |
| 3003 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 3004 | Return ``True`` if the process exited due to a signal, otherwise return |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3005 | ``False``. |
| 3006 | |
| 3007 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3008 | |
| 3009 | |
| 3010 | .. function:: WIFEXITED(status) |
| 3011 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 3012 | 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] | 3013 | otherwise return ``False``. |
| 3014 | |
| 3015 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3016 | |
| 3017 | |
| 3018 | .. function:: WEXITSTATUS(status) |
| 3019 | |
| 3020 | If ``WIFEXITED(status)`` is true, return the integer parameter to the |
| 3021 | :manpage:`exit(2)` system call. Otherwise, the return value is meaningless. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3022 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 3023 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3024 | |
| 3025 | |
| 3026 | .. function:: WSTOPSIG(status) |
| 3027 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3028 | Return the signal which caused the process to stop. |
| 3029 | |
| 3030 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3031 | |
| 3032 | |
| 3033 | .. function:: WTERMSIG(status) |
| 3034 | |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3035 | Return the signal which caused the process to exit. |
| 3036 | |
| 3037 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3038 | |
| 3039 | |
Benjamin Peterson | 94b580d | 2011-08-02 17:30:04 -0500 | [diff] [blame] | 3040 | Interface to the scheduler |
| 3041 | -------------------------- |
| 3042 | |
| 3043 | These functions control how a process is allocated CPU time by the operating |
| 3044 | system. They are only available on some Unix platforms. For more detailed |
| 3045 | information, consult your Unix manpages. |
| 3046 | |
| 3047 | .. versionadded:: 3.3 |
| 3048 | |
| 3049 | The following scheduling policies are exposed if they are a supported by the |
| 3050 | operating system. |
| 3051 | |
| 3052 | .. data:: SCHED_OTHER |
| 3053 | |
| 3054 | The default scheduling policy. |
| 3055 | |
| 3056 | .. data:: SCHED_BATCH |
| 3057 | |
| 3058 | Scheduling policy for CPU-intensive processes that tries to preserve |
| 3059 | interactivity on the rest of the computer. |
| 3060 | |
| 3061 | .. data:: SCHED_IDLE |
| 3062 | |
| 3063 | Scheduling policy for extremely low priority background tasks. |
| 3064 | |
| 3065 | .. data:: SCHED_SPORADIC |
| 3066 | |
| 3067 | Scheduling policy for sporadic server programs. |
| 3068 | |
| 3069 | .. data:: SCHED_FIFO |
| 3070 | |
| 3071 | A First In First Out scheduling policy. |
| 3072 | |
| 3073 | .. data:: SCHED_RR |
| 3074 | |
| 3075 | A round-robin scheduling policy. |
| 3076 | |
| 3077 | .. data:: SCHED_RESET_ON_FORK |
| 3078 | |
| 3079 | This flag can OR'ed with any other scheduling policy. When a process with |
| 3080 | this flag set forks, its child's scheduling policy and priority are reset to |
| 3081 | the default. |
| 3082 | |
| 3083 | |
| 3084 | .. class:: sched_param(sched_priority) |
| 3085 | |
| 3086 | This class represents tunable scheduling parameters used in |
| 3087 | :func:`sched_setparam`, :func:`sched_setscheduler`, and |
| 3088 | :func:`sched_getparam`. It is immutable. |
| 3089 | |
| 3090 | At the moment, there is only one possible parameter: |
| 3091 | |
| 3092 | .. attribute:: sched_priority |
| 3093 | |
| 3094 | The scheduling priority for a scheduling policy. |
| 3095 | |
| 3096 | |
| 3097 | .. function:: sched_get_priority_min(policy) |
| 3098 | |
| 3099 | Get the minimum priority value for *policy*. *policy* is one of the |
| 3100 | scheduling policy constants above. |
| 3101 | |
| 3102 | |
| 3103 | .. function:: sched_get_priority_max(policy) |
| 3104 | |
| 3105 | Get the maximum priority value for *policy*. *policy* is one of the |
| 3106 | scheduling policy constants above. |
| 3107 | |
| 3108 | |
| 3109 | .. function:: sched_setscheduler(pid, policy, param) |
| 3110 | |
| 3111 | Set the scheduling policy for the process with PID *pid*. A *pid* of 0 means |
| 3112 | the calling process. *policy* is one of the scheduling policy constants |
| 3113 | above. *param* is a :class:`sched_param` instance. |
| 3114 | |
| 3115 | |
| 3116 | .. function:: sched_getscheduler(pid) |
| 3117 | |
| 3118 | Return the scheduling policy for the process with PID *pid*. A *pid* of 0 |
| 3119 | means the calling process. The result is one of the scheduling policy |
| 3120 | constants above. |
| 3121 | |
| 3122 | |
| 3123 | .. function:: sched_setparam(pid, param) |
| 3124 | |
| 3125 | Set a scheduling parameters for the process with PID *pid*. A *pid* of 0 means |
| 3126 | the calling process. *param* is a :class:`sched_param` instance. |
| 3127 | |
| 3128 | |
| 3129 | .. function:: sched_getparam(pid) |
| 3130 | |
| 3131 | Return the scheduling parameters as a :class:`sched_param` instance for the |
| 3132 | process with PID *pid*. A *pid* of 0 means the calling process. |
| 3133 | |
| 3134 | |
| 3135 | .. function:: sched_rr_get_interval(pid) |
| 3136 | |
| 3137 | Return the round-robin quantum in seconds for the process with PID *pid*. A |
| 3138 | *pid* of 0 means the calling process. |
| 3139 | |
| 3140 | |
| 3141 | .. function:: sched_yield() |
| 3142 | |
| 3143 | Voluntarily relinquish the CPU. |
| 3144 | |
| 3145 | |
Benjamin Peterson | 94b580d | 2011-08-02 17:30:04 -0500 | [diff] [blame] | 3146 | .. function:: sched_setaffinity(pid, mask) |
| 3147 | |
Antoine Pitrou | 8486987 | 2012-08-04 16:16:35 +0200 | [diff] [blame] | 3148 | Restrict the process with PID *pid* (or the current process if zero) to a |
| 3149 | set of CPUs. *mask* is an iterable of integers representing the set of |
| 3150 | CPUs to which the process should be restricted. |
Benjamin Peterson | 94b580d | 2011-08-02 17:30:04 -0500 | [diff] [blame] | 3151 | |
| 3152 | |
Antoine Pitrou | 8486987 | 2012-08-04 16:16:35 +0200 | [diff] [blame] | 3153 | .. function:: sched_getaffinity(pid) |
Benjamin Peterson | 94b580d | 2011-08-02 17:30:04 -0500 | [diff] [blame] | 3154 | |
Antoine Pitrou | 8486987 | 2012-08-04 16:16:35 +0200 | [diff] [blame] | 3155 | Return the set of CPUs the process with PID *pid* (or the current process |
| 3156 | if zero) is restricted to. |
Benjamin Peterson | 94b580d | 2011-08-02 17:30:04 -0500 | [diff] [blame] | 3157 | |
Victor Stinner | 15f3d1e | 2012-08-04 20:57:48 +0200 | [diff] [blame] | 3158 | .. seealso:: |
| 3159 | :func:`multiprocessing.cpu_count` returns the number of CPUs in the |
| 3160 | system. |
| 3161 | |
Benjamin Peterson | 94b580d | 2011-08-02 17:30:04 -0500 | [diff] [blame] | 3162 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3163 | .. _os-path: |
| 3164 | |
| 3165 | Miscellaneous System Information |
| 3166 | -------------------------------- |
| 3167 | |
| 3168 | |
| 3169 | .. function:: confstr(name) |
| 3170 | |
| 3171 | Return string-valued system configuration values. *name* specifies the |
| 3172 | configuration value to retrieve; it may be a string which is the name of a |
| 3173 | defined system value; these names are specified in a number of standards (POSIX, |
| 3174 | Unix 95, Unix 98, and others). Some platforms define additional names as well. |
| 3175 | The names known to the host operating system are given as the keys of the |
| 3176 | ``confstr_names`` dictionary. For configuration variables not included in that |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3177 | mapping, passing an integer for *name* is also accepted. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3178 | |
| 3179 | If the configuration value specified by *name* isn't defined, ``None`` is |
| 3180 | returned. |
| 3181 | |
| 3182 | If *name* is a string and is not known, :exc:`ValueError` is raised. If a |
| 3183 | specific value for *name* is not supported by the host system, even if it is |
| 3184 | included in ``confstr_names``, an :exc:`OSError` is raised with |
| 3185 | :const:`errno.EINVAL` for the error number. |
| 3186 | |
Georg Brandl | 8a5555f | 2012-06-24 13:29:09 +0200 | [diff] [blame] | 3187 | Availability: Unix. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3188 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3189 | |
| 3190 | .. data:: confstr_names |
| 3191 | |
| 3192 | Dictionary mapping names accepted by :func:`confstr` to the integer values |
| 3193 | 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] | 3194 | determine the set of names known to the system. |
| 3195 | |
| 3196 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3197 | |
| 3198 | |
| 3199 | .. function:: getloadavg() |
| 3200 | |
Christian Heimes | a62da1d | 2008-01-12 19:39:10 +0000 | [diff] [blame] | 3201 | Return the number of processes in the system run queue averaged over the last |
| 3202 | 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] | 3203 | unobtainable. |
| 3204 | |
| 3205 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3206 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3207 | |
| 3208 | .. function:: sysconf(name) |
| 3209 | |
| 3210 | Return integer-valued system configuration values. If the configuration value |
| 3211 | specified by *name* isn't defined, ``-1`` is returned. The comments regarding |
| 3212 | the *name* parameter for :func:`confstr` apply here as well; the dictionary that |
| 3213 | provides information on the known names is given by ``sysconf_names``. |
Benjamin Peterson | f650e46 | 2010-05-06 23:03:05 +0000 | [diff] [blame] | 3214 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 3215 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3216 | |
| 3217 | |
| 3218 | .. data:: sysconf_names |
| 3219 | |
| 3220 | Dictionary mapping names accepted by :func:`sysconf` to the integer values |
| 3221 | 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] | 3222 | determine the set of names known to the system. |
| 3223 | |
| 3224 | Availability: Unix. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3225 | |
Christian Heimes | faf2f63 | 2008-01-06 16:59:19 +0000 | [diff] [blame] | 3226 | The following data values are used to support path manipulation operations. These |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3227 | are defined for all platforms. |
| 3228 | |
| 3229 | Higher-level operations on pathnames are defined in the :mod:`os.path` module. |
| 3230 | |
| 3231 | |
| 3232 | .. data:: curdir |
| 3233 | |
| 3234 | 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] | 3235 | directory. This is ``'.'`` for Windows and POSIX. Also available via |
| 3236 | :mod:`os.path`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3237 | |
| 3238 | |
| 3239 | .. data:: pardir |
| 3240 | |
| 3241 | 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] | 3242 | directory. This is ``'..'`` for Windows and POSIX. Also available via |
| 3243 | :mod:`os.path`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3244 | |
| 3245 | |
| 3246 | .. data:: sep |
| 3247 | |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 3248 | The character used by the operating system to separate pathname components. |
| 3249 | This is ``'/'`` for POSIX and ``'\\'`` for Windows. Note that knowing this |
| 3250 | is not sufficient to be able to parse or concatenate pathnames --- use |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3251 | :func:`os.path.split` and :func:`os.path.join` --- but it is occasionally |
| 3252 | useful. Also available via :mod:`os.path`. |
| 3253 | |
| 3254 | |
| 3255 | .. data:: altsep |
| 3256 | |
| 3257 | An alternative character used by the operating system to separate pathname |
| 3258 | components, or ``None`` if only one separator character exists. This is set to |
| 3259 | ``'/'`` on Windows systems where ``sep`` is a backslash. Also available via |
| 3260 | :mod:`os.path`. |
| 3261 | |
| 3262 | |
| 3263 | .. data:: extsep |
| 3264 | |
| 3265 | The character which separates the base filename from the extension; for example, |
| 3266 | the ``'.'`` in :file:`os.py`. Also available via :mod:`os.path`. |
| 3267 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3268 | |
| 3269 | .. data:: pathsep |
| 3270 | |
| 3271 | The character conventionally used by the operating system to separate search |
| 3272 | path components (as in :envvar:`PATH`), such as ``':'`` for POSIX or ``';'`` for |
| 3273 | Windows. Also available via :mod:`os.path`. |
| 3274 | |
| 3275 | |
| 3276 | .. data:: defpath |
| 3277 | |
| 3278 | The default search path used by :func:`exec\*p\*` and :func:`spawn\*p\*` if the |
| 3279 | environment doesn't have a ``'PATH'`` key. Also available via :mod:`os.path`. |
| 3280 | |
| 3281 | |
| 3282 | .. data:: linesep |
| 3283 | |
| 3284 | The string used to separate (or, rather, terminate) lines on the current |
Georg Brandl | c575c90 | 2008-09-13 17:46:05 +0000 | [diff] [blame] | 3285 | platform. This may be a single character, such as ``'\n'`` for POSIX, or |
| 3286 | multiple characters, for example, ``'\r\n'`` for Windows. Do not use |
| 3287 | *os.linesep* as a line terminator when writing files opened in text mode (the |
| 3288 | default); use a single ``'\n'`` instead, on all platforms. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3289 | |
| 3290 | |
| 3291 | .. data:: devnull |
| 3292 | |
Georg Brandl | 850a990 | 2010-05-21 22:04:32 +0000 | [diff] [blame] | 3293 | The file path of the null device. For example: ``'/dev/null'`` for |
| 3294 | POSIX, ``'nul'`` for Windows. Also available via :mod:`os.path`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3295 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3296 | |
| 3297 | .. _os-miscfunc: |
| 3298 | |
| 3299 | Miscellaneous Functions |
| 3300 | ----------------------- |
| 3301 | |
| 3302 | |
| 3303 | .. function:: urandom(n) |
| 3304 | |
| 3305 | Return a string of *n* random bytes suitable for cryptographic use. |
| 3306 | |
| 3307 | This function returns random bytes from an OS-specific randomness source. The |
| 3308 | returned data should be unpredictable enough for cryptographic applications, |
Georg Brandl | f62445a | 2012-06-24 13:31:20 +0200 | [diff] [blame] | 3309 | though its exact quality depends on the OS implementation. On a Unix-like |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 3310 | system this will query /dev/urandom, and on Windows it will use CryptGenRandom. |
| 3311 | If a randomness source is not found, :exc:`NotImplementedError` will be raised. |