Guido van Rossum | 5c97167 | 1996-07-22 15:23:25 +0000 | [diff] [blame] | 1 | # |
| 2 | # Start of posixfile.py |
| 3 | # |
| 4 | |
| 5 | # |
| 6 | # Extended file operations |
| 7 | # |
| 8 | # f = posixfile.open(filename, [mode, [bufsize]]) |
| 9 | # will create a new posixfile object |
| 10 | # |
| 11 | # f = posixfile.fileopen(fileobject) |
| 12 | # will create a posixfile object from a builtin file object |
| 13 | # |
| 14 | # f.file() |
| 15 | # will return the original builtin file object |
| 16 | # |
| 17 | # f.dup() |
| 18 | # will return a new file object based on a new filedescriptor |
| 19 | # |
| 20 | # f.dup2(fd) |
| 21 | # will return a new file object based on the given filedescriptor |
| 22 | # |
| 23 | # f.flags(mode) |
| 24 | # will turn on the associated flag (merge) |
| 25 | # mode can contain the following characters: |
| 26 | # |
| 27 | # (character representing a flag) |
| 28 | # a append only flag |
| 29 | # c close on exec flag |
| 30 | # n no delay flag |
| 31 | # s synchronization flag |
| 32 | # (modifiers) |
| 33 | # ! turn flags 'off' instead of default 'on' |
| 34 | # = copy flags 'as is' instead of default 'merge' |
| 35 | # ? return a string in which the characters represent the flags |
| 36 | # that are set |
| 37 | # |
| 38 | # note: - the '!' and '=' modifiers are mutually exclusive. |
| 39 | # - the '?' modifier will return the status of the flags after they |
| 40 | # have been changed by other characters in the mode string |
| 41 | # |
| 42 | # f.lock(mode [, len [, start [, whence]]]) |
| 43 | # will (un)lock a region |
| 44 | # mode can contain the following characters: |
| 45 | # |
| 46 | # (character representing type of lock) |
| 47 | # u unlock |
| 48 | # r read lock |
| 49 | # w write lock |
| 50 | # (modifiers) |
| 51 | # | wait until the lock can be granted |
| 52 | # ? return the first lock conflicting with the requested lock |
| 53 | # or 'None' if there is no conflict. The lock returned is in the |
| 54 | # format (mode, len, start, whence, pid) where mode is a |
| 55 | # character representing the type of lock ('r' or 'w') |
| 56 | # |
| 57 | # note: - the '?' modifier prevents a region from being locked; it is |
| 58 | # query only |
| 59 | # |
| 60 | |
| 61 | class _posixfile_: |
| 62 | states = ['open', 'closed'] |
| 63 | |
| 64 | # |
| 65 | # Internal routines |
| 66 | # |
| 67 | def __repr__(self): |
| 68 | file = self._file_ |
| 69 | return "<%s posixfile '%s', mode '%s' at %s>" % \ |
| 70 | (self.states[file.closed], file.name, file.mode, \ |
| 71 | hex(id(self))[2:]) |
| 72 | |
| 73 | def __del__(self): |
| 74 | self._file_.close() |
| 75 | |
| 76 | # |
| 77 | # Initialization routines |
| 78 | # |
| 79 | def open(self, name, mode='r', bufsize=-1): |
| 80 | import __builtin__ |
| 81 | return self.fileopen(__builtin__.open(name, mode, bufsize)) |
| 82 | |
| 83 | def fileopen(self, file): |
| 84 | if `type(file)` != "<type 'file'>": |
| 85 | raise TypeError, 'posixfile.fileopen() arg must be file object' |
| 86 | self._file_ = file |
| 87 | # Copy basic file methods |
| 88 | for method in file.__methods__: |
| 89 | setattr(self, method, getattr(file, method)) |
| 90 | return self |
| 91 | |
| 92 | # |
| 93 | # New methods |
| 94 | # |
| 95 | def file(self): |
| 96 | return self._file_ |
| 97 | |
| 98 | def dup(self): |
| 99 | import posix |
| 100 | |
| 101 | try: ignore = posix.fdopen |
| 102 | except: raise AttributeError, 'dup() method unavailable' |
| 103 | |
| 104 | return posix.fdopen(posix.dup(self._file_.fileno()), self._file_.mode) |
| 105 | |
| 106 | def dup2(self, fd): |
| 107 | import posix |
| 108 | |
| 109 | try: ignore = posix.fdopen |
| 110 | except: raise AttributeError, 'dup() method unavailable' |
| 111 | |
| 112 | posix.dup2(self._file_.fileno(), fd) |
| 113 | return posix.fdopen(fd, self._file_.mode) |
| 114 | |
| 115 | def flags(self, *which): |
| 116 | import fcntl, FCNTL |
| 117 | |
| 118 | if which: |
| 119 | if len(which) > 1: |
| 120 | raise TypeError, 'Too many arguments' |
| 121 | which = which[0] |
| 122 | else: which = '?' |
| 123 | |
| 124 | l_flags = 0 |
| 125 | if 'n' in which: l_flags = l_flags | FCNTL.O_NDELAY |
| 126 | if 'a' in which: l_flags = l_flags | FCNTL.O_APPEND |
| 127 | if 's' in which: l_flags = l_flags | FCNTL.O_SYNC |
| 128 | |
| 129 | file = self._file_ |
| 130 | |
| 131 | if '=' not in which: |
| 132 | cur_fl = fcntl.fcntl(file.fileno(), FCNTL.F_GETFL, 0) |
| 133 | if '!' in which: l_flags = cur_fl & ~ l_flags |
| 134 | else: l_flags = cur_fl | l_flags |
| 135 | |
| 136 | l_flags = fcntl.fcntl(file.fileno(), FCNTL.F_SETFL, l_flags) |
| 137 | |
| 138 | if 'c' in which: |
| 139 | arg = ('!' not in which) # 0 is don't, 1 is do close on exec |
| 140 | l_flags = fcntl.fcntl(file.fileno(), FCNTL.F_SETFD, arg) |
| 141 | |
| 142 | if '?' in which: |
| 143 | which = '' # Return current flags |
| 144 | l_flags = fcntl.fcntl(file.fileno(), FCNTL.F_GETFL, 0) |
| 145 | if FCNTL.O_APPEND & l_flags: which = which + 'a' |
| 146 | if fcntl.fcntl(file.fileno(), FCNTL.F_GETFD, 0) & 1: |
| 147 | which = which + 'c' |
| 148 | if FCNTL.O_NDELAY & l_flags: which = which + 'n' |
| 149 | if FCNTL.O_SYNC & l_flags: which = which + 's' |
| 150 | return which |
| 151 | |
| 152 | def lock(self, how, *args): |
| 153 | import struct, fcntl, FCNTL |
| 154 | |
| 155 | if 'w' in how: l_type = FCNTL.F_WRLCK |
| 156 | elif 'r' in how: l_type = FCNTL.F_RDLCK |
| 157 | elif 'u' in how: l_type = FCNTL.F_UNLCK |
| 158 | else: raise TypeError, 'no type of lock specified' |
| 159 | |
| 160 | if '|' in how: cmd = FCNTL.F_SETLKW |
| 161 | elif '?' in how: cmd = FCNTL.F_GETLK |
| 162 | else: cmd = FCNTL.F_SETLK |
| 163 | |
| 164 | l_whence = 0 |
| 165 | l_start = 0 |
| 166 | l_len = 0 |
| 167 | |
| 168 | if len(args) == 1: |
| 169 | l_len = args[0] |
| 170 | elif len(args) == 2: |
| 171 | l_len, l_start = args |
| 172 | elif len(args) == 3: |
| 173 | l_len, l_start, l_whence = args |
| 174 | elif len(args) > 3: |
| 175 | raise TypeError, 'too many arguments' |
| 176 | |
Guido van Rossum | a8763e5 | 1996-08-26 18:33:32 +0000 | [diff] [blame] | 177 | # Hack by davem@magnet.com to get locking to go on freebsd; |
| 178 | # additions for AIX by Vladimir.Marangozov@imag.fr |
Guido van Rossum | 3bb710d | 1996-07-30 16:35:26 +0000 | [diff] [blame] | 179 | import sys, os |
| 180 | if sys.platform == 'freebsd2': |
| 181 | flock = struct.pack('lxxxxlxxxxlhh', \ |
| 182 | l_start, l_len, os.getpid(), l_type, l_whence) |
Guido van Rossum | a8763e5 | 1996-08-26 18:33:32 +0000 | [diff] [blame] | 183 | elif sys.platform in ['aix3', 'aix4']: |
| 184 | flock = struct.pack('hhlllii', \ |
| 185 | l_type, l_whence, l_start, l_len, 0, 0, 0) |
Guido van Rossum | 3bb710d | 1996-07-30 16:35:26 +0000 | [diff] [blame] | 186 | else: |
| 187 | flock = struct.pack('hhllhh', \ |
| 188 | l_type, l_whence, l_start, l_len, 0, 0) |
| 189 | |
Guido van Rossum | 5c97167 | 1996-07-22 15:23:25 +0000 | [diff] [blame] | 190 | flock = fcntl.fcntl(self._file_.fileno(), cmd, flock) |
| 191 | |
| 192 | if '?' in how: |
Guido van Rossum | 3bb710d | 1996-07-30 16:35:26 +0000 | [diff] [blame] | 193 | if sys.platform == 'freebsd2': |
| 194 | l_start, l_len, l_pid, l_type, l_whence = \ |
| 195 | struct.unpack('lxxxxlxxxxlhh', flock) |
Guido van Rossum | a8763e5 | 1996-08-26 18:33:32 +0000 | [diff] [blame] | 196 | elif sys.platform in ['aix3', 'aix4']: |
| 197 | l_type, l_whence, l_start, l_len, l_sysid, l_pid, l_vfs = \ |
| 198 | struct.unpack('hhlllii', flock) |
Guido van Rossum | 28d4ba2 | 1996-09-11 19:07:45 +0000 | [diff] [blame] | 199 | elif sys.platform == "linux2": |
| 200 | l_type, l_whence, l_start, l_len, l_pid, l_sysid = \ |
| 201 | struct.unpack('hhllhh', flock) |
Guido van Rossum | 3bb710d | 1996-07-30 16:35:26 +0000 | [diff] [blame] | 202 | else: |
| 203 | l_type, l_whence, l_start, l_len, l_sysid, l_pid = \ |
| 204 | struct.unpack('hhllhh', flock) |
| 205 | |
Guido van Rossum | 5c97167 | 1996-07-22 15:23:25 +0000 | [diff] [blame] | 206 | if l_type != FCNTL.F_UNLCK: |
| 207 | if l_type == FCNTL.F_RDLCK: |
| 208 | return 'r', l_len, l_start, l_whence, l_pid |
| 209 | else: |
| 210 | return 'w', l_len, l_start, l_whence, l_pid |
| 211 | |
| 212 | # |
| 213 | # Public routine to obtain a posixfile object |
| 214 | # |
| 215 | def open(name, mode='r', bufsize=-1): |
| 216 | return _posixfile_().open(name, mode, bufsize) |
| 217 | |
| 218 | def fileopen(file): |
| 219 | return _posixfile_().fileopen(file) |
| 220 | |
| 221 | # |
| 222 | # Constants |
| 223 | # |
| 224 | SEEK_SET = 0 |
| 225 | SEEK_CUR = 1 |
| 226 | SEEK_END = 2 |
| 227 | |
| 228 | # |
| 229 | # End of posixfile.py |
| 230 | # |