source file: /System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/os.py
file stats: 341 lines, 4 executed: 1.2% covered
   1. r"""OS routines for Mac, DOS, NT, or Posix depending on what system we're on.
   2. 
   3. This exports:
   4.   - all functions from posix, nt, os2, mac, or ce, e.g. unlink, stat, etc.
   5.   - os.path is one of the modules posixpath, ntpath, or macpath
   6.   - os.name is 'posix', 'nt', 'os2', 'mac', 'ce' or 'riscos'
   7.   - os.curdir is a string representing the current directory ('.' or ':')
   8.   - os.pardir is a string representing the parent directory ('..' or '::')
   9.   - os.sep is the (or a most common) pathname separator ('/' or ':' or '\\')
  10.   - os.extsep is the extension separator ('.' or '/')
  11.   - os.altsep is the alternate pathname separator (None or '/')
  12.   - os.pathsep is the component separator used in $PATH etc
  13.   - os.linesep is the line separator in text files ('\r' or '\n' or '\r\n')
  14.   - os.defpath is the default search path for executables
  15. 
  16. Programs that import and use 'os' stand a better chance of being
  17. portable between different platforms.  Of course, they must then
  18. only use functions that are defined by all platforms (e.g., unlink
  19. and opendir), and leave all pathname manipulation to os.path
  20. (e.g., split and join).
  21. """
  22. 
  23. #'
  24. 
  25. import sys
  26. 
  27. _names = sys.builtin_module_names
  28. 
  29. # Note:  more names are added to __all__ later.
  30. __all__ = ["altsep", "curdir", "pardir", "sep", "pathsep", "linesep",
  31.            "defpath", "name", "path"]
  32. 
  33. def _get_exports_list(module):
  34.     try:
  35.         return list(module.__all__)
  36.     except AttributeError:
  37.         return [n for n in dir(module) if n[0] != '_']
  38. 
  39. if 'posix' in _names:
  40.     name = 'posix'
  41.     linesep = '\n'
  42.     from posix import *
  43.     try:
  44.         from posix import _exit
  45.     except ImportError:
  46.         pass
  47.     import posixpath as path
  48. 
  49.     import posix
  50.     __all__.extend(_get_exports_list(posix))
  51.     del posix
  52. 
  53. elif 'nt' in _names:
  54.     name = 'nt'
  55.     linesep = '\r\n'
  56.     from nt import *
  57.     try:
  58.         from nt import _exit
  59.     except ImportError:
  60.         pass
  61.     import ntpath as path
  62. 
  63.     import nt
  64.     __all__.extend(_get_exports_list(nt))
  65.     del nt
  66. 
  67. elif 'os2' in _names:
  68.     name = 'os2'
  69.     linesep = '\r\n'
  70.     from os2 import *
  71.     try:
  72.         from os2 import _exit
  73.     except ImportError:
  74.         pass
  75.     if sys.version.find('EMX GCC') == -1:
  76.         import ntpath as path
  77.     else:
  78.         import os2emxpath as path
  79. 
  80.     import os2
  81.     __all__.extend(_get_exports_list(os2))
  82.     del os2
  83. 
  84. elif 'mac' in _names:
  85.     name = 'mac'
  86.     linesep = '\r'
  87.     from mac import *
  88.     try:
  89.         from mac import _exit
  90.     except ImportError:
  91.         pass
  92.     import macpath as path
  93. 
  94.     import mac
  95.     __all__.extend(_get_exports_list(mac))
  96.     del mac
  97. 
  98. elif 'ce' in _names:
  99.     name = 'ce'
 100.     linesep = '\r\n'
 101.     from ce import *
 102.     try:
 103.         from ce import _exit
 104.     except ImportError:
 105.         pass
 106.     # We can use the standard Windows path.
 107.     import ntpath as path
 108. 
 109.     import ce
 110.     __all__.extend(_get_exports_list(ce))
 111.     del ce
 112. 
 113. elif 'riscos' in _names:
 114.     name = 'riscos'
 115.     linesep = '\n'
 116.     from riscos import *
 117.     try:
 118.         from riscos import _exit
 119.     except ImportError:
 120.         pass
 121.     import riscospath as path
 122. 
 123.     import riscos
 124.     __all__.extend(_get_exports_list(riscos))
 125.     del riscos
 126. 
 127. else:
 128.     raise ImportError, 'no os specific module found'
 129. 
 130. sys.modules['os.path'] = path
 131. from os.path import curdir, pardir, sep, pathsep, defpath, extsep, altsep
 132. 
 133. del _names
 134. 
 135. #'
 136. 
 137. # Super directory utilities.
 138. # (Inspired by Eric Raymond; the doc strings are mostly his)
 139. 
 140. def makedirs(name, mode=0777):
 141.     """makedirs(path [, mode=0777])
 142. 
 143.     Super-mkdir; create a leaf directory and all intermediate ones.
 144.     Works like mkdir, except that any intermediate path segment (not
 145.     just the rightmost) will be created if it does not exist.  This is
 146.     recursive.
 147. 
 148.     """
 149.     head, tail = path.split(name)
 150.     if not tail:
 151.         head, tail = path.split(head)
 152.     if head and tail and not path.exists(head):
 153.         makedirs(head, mode)
 154.     mkdir(name, mode)
 155. 
 156. def removedirs(name):
 157.     """removedirs(path)
 158. 
 159.     Super-rmdir; remove a leaf directory and empty all intermediate
 160.     ones.  Works like rmdir except that, if the leaf directory is
 161.     successfully removed, directories corresponding to rightmost path
 162.     segments will be pruned away until either the whole path is
 163.     consumed or an error occurs.  Errors during this latter phase are
 164.     ignored -- they generally mean that a directory was not empty.
 165. 
 166.     """
 167.     rmdir(name)
 168.     head, tail = path.split(name)
 169.     if not tail:
 170.         head, tail = path.split(head)
 171.     while head and tail:
 172.         try:
 173.             rmdir(head)
 174.         except error:
 175.             break
 176.         head, tail = path.split(head)
 177. 
 178. def renames(old, new):
 179.     """renames(old, new)
 180. 
 181.     Super-rename; create directories as necessary and delete any left
 182.     empty.  Works like rename, except creation of any intermediate
 183.     directories needed to make the new pathname good is attempted
 184.     first.  After the rename, directories corresponding to rightmost
 185.     path segments of the old name will be pruned way until either the
 186.     whole path is consumed or a nonempty directory is found.
 187. 
 188.     Note: this function can fail with the new directory structure made
 189.     if you lack permissions needed to unlink the leaf directory or
 190.     file.
 191. 
 192.     """
 193.     head, tail = path.split(new)
 194.     if head and tail and not path.exists(head):
 195.         makedirs(head)
 196.     rename(old, new)
 197.     head, tail = path.split(old)
 198.     if head and tail:
 199.         try:
 200.             removedirs(head)
 201.         except error:
 202.             pass
 203. 
 204. __all__.extend(["makedirs", "removedirs", "renames"])
 205. 
 206. def walk(top, topdown=True, onerror=None):
 207.     """Directory tree generator.
 208. 
 209.     For each directory in the directory tree rooted at top (including top
 210.     itself, but excluding '.' and '..'), yields a 3-tuple
 211. 
 212.         dirpath, dirnames, filenames
 213. 
 214.     dirpath is a string, the path to the directory.  dirnames is a list of
 215.     the names of the subdirectories in dirpath (excluding '.' and '..').
 216.     filenames is a list of the names of the non-directory files in dirpath.
 217.     Note that the names in the lists are just names, with no path components.
 218.     To get a full path (which begins with top) to a file or directory in
 219.     dirpath, do os.path.join(dirpath, name).
 220. 
 221.     If optional arg 'topdown' is true or not specified, the triple for a
 222.     directory is generated before the triples for any of its subdirectories
 223.     (directories are generated top down).  If topdown is false, the triple
 224.     for a directory is generated after the triples for all of its
 225.     subdirectories (directories are generated bottom up).
 226. 
 227.     When topdown is true, the caller can modify the dirnames list in-place
 228.     (e.g., via del or slice assignment), and walk will only recurse into the
 229.     subdirectories whose names remain in dirnames; this can be used to prune
 230.     the search, or to impose a specific order of visiting.  Modifying
 231.     dirnames when topdown is false is ineffective, since the directories in
 232.     dirnames have already been generated by the time dirnames itself is
 233.     generated.
 234. 
 235.     By default errors from the os.listdir() call are ignored.  If
 236.     optional arg 'onerror' is specified, it should be a function; it
 237.     will be called with one argument, an os.error instance.  It can
 238.     report the error to continue with the walk, or raise the exception
 239.     to abort the walk.  Note that the filename is available as the
 240.     filename attribute of the exception object.
 241. 
 242.     Caution:  if you pass a relative pathname for top, don't change the
 243.     current working directory between resumptions of walk.  walk never
 244.     changes the current directory, and assumes that the client doesn't
 245.     either.
 246. 
 247.     Example:
 248. 
 249.     from os.path import join, getsize
 250.     for root, dirs, files in walk('python/Lib/email'):
 251.         print root, "consumes",
 252.         print sum([getsize(join(root, name)) for name in files]),
 253.         print "bytes in", len(files), "non-directory files"
 254.         if 'CVS' in dirs:
 255.             dirs.remove('CVS')  # don't visit CVS directories
 256.     """
 257. 
 258.     from os.path import join, isdir, islink
 259. 
 260.     # We may not have read permission for top, in which case we can't
 261.     # get a list of the files the directory contains.  os.path.walk
 262.     # always suppressed the exception then, rather than blow up for a
 263.     # minor reason when (say) a thousand readable directories are still
 264.     # left to visit.  That logic is copied here.
 265.     try:
 266.         # Note that listdir and error are globals in this module due
 267.         # to earlier import-*.
 268.         names = listdir(top)
 269.     except error, err:
 270.         if onerror is not None:
 271.             onerror(err)
 272.         return
 273. 
 274.     dirs, nondirs = [], []
 275.     for name in names:
 276.         if isdir(join(top, name)):
 277.             dirs.append(name)
 278.         else:
 279.             nondirs.append(name)
 280. 
 281.     if topdown:
 282.         yield top, dirs, nondirs
 283.     for name in dirs:
 284.         path = join(top, name)
 285.         if not islink(path):
 286.             for x in walk(path, topdown, onerror):
 287.                 yield x
 288.     if not topdown:
 289.         yield top, dirs, nondirs
 290. 
 291. __all__.append("walk")
 292. 
 293. # Make sure os.environ exists, at least
 294. try:
 295.     environ
 296. except NameError:
 297.     environ = {}
 298. 
 299. def execl(file, *args):
 300.     """execl(file, *args)
 301. 
 302.     Execute the executable file with argument list args, replacing the
 303.     current process. """
 304.     execv(file, args)
 305. 
 306. def execle(file, *args):
 307.     """execle(file, *args, env)
 308. 
 309.     Execute the executable file with argument list args and
 310.     environment env, replacing the current process. """
 311.     env = args[-1]
 312.     execve(file, args[:-1], env)
 313. 
 314. def execlp(file, *args):
 315.     """execlp(file, *args)
 316. 
 317.     Execute the executable file (which is searched for along $PATH)
 318.     with argument list args, replacing the current process. """
 319.     execvp(file, args)
 320. 
 321. def execlpe(file, *args):
 322.     """execlpe(file, *args, env)
 323. 
 324.     Execute the executable file (which is searched for along $PATH)
 325.     with argument list args and environment env, replacing the current
 326.     process. """
 327.     env = args[-1]
 328.     execvpe(file, args[:-1], env)
 329. 
 330. def execvp(file, args):
 331.     """execp(file, args)
 332. 
 333.     Execute the executable file (which is searched for along $PATH)
 334.     with argument list args, replacing the current process.
 335.     args may be a list or tuple of strings. """
 336.     _execvpe(file, args)
 337. 
 338. def execvpe(file, args, env):
 339.     """execvpe(file, args, env)
 340. 
 341.     Execute the executable file (which is searched for along $PATH)
 342.     with argument list args and environment env , replacing the
 343.     current process.
 344.     args may be a list or tuple of strings. """
 345.     _execvpe(file, args, env)
 346. 
 347. __all__.extend(["execl","execle","execlp","execlpe","execvp","execvpe"])
 348. 
 349. def _execvpe(file, args, env=None):
 350.     from errno import ENOENT, ENOTDIR
 351. 
 352.     if env is not None:
 353.         func = execve
 354.         argrest = (args, env)
 355.     else:
 356.         func = execv
 357.         argrest = (args,)
 358.         env = environ
 359. 
 360.     head, tail = path.split(file)
 361.     if head:
 362.         func(file, *argrest)
 363.         return
 364.     if 'PATH' in env:
 365.         envpath = env['PATH']
 366.     else:
 367.         envpath = defpath
 368.     PATH = envpath.split(pathsep)
 369.     saved_exc = None
 370.     saved_tb = None
 371.     for dir in PATH:
 372.         fullname = path.join(dir, file)
 373.         try:
 374.             func(fullname, *argrest)
 375.         except error, e:
 376.             tb = sys.exc_info()[2]
 377.             if (e.errno != ENOENT and e.errno != ENOTDIR
 378.                 and saved_exc is None):
 379.                 saved_exc = e
 380.                 saved_tb = tb
 381.     if saved_exc:
 382.         raise error, saved_exc, saved_tb
 383.     raise error, e, tb
 384. 
 385. # Change environ to automatically call putenv() if it exists
 386. try:
 387.     # This will fail if there's no putenv
 388.     putenv
 389. except NameError:
 390.     pass
 391. else:
 392.     import UserDict
 393. 
 394.     # Fake unsetenv() for Windows
 395.     # not sure about os2 here but
 396.     # I'm guessing they are the same.
 397. 
 398.     if name in ('os2', 'nt'):
 399.         def unsetenv(key):
 400.             putenv(key, "")
 401. 
 402.     if name == "riscos":
 403.         # On RISC OS, all env access goes through getenv and putenv
 404.         from riscosenviron import _Environ
 405.     elif name in ('os2', 'nt'):  # Where Env Var Names Must Be UPPERCASE
 406.         # But we store them as upper case
 407.         class _Environ(UserDict.IterableUserDict):
 408.             def __init__(self, environ):
 409.                 UserDict.UserDict.__init__(self)
 410.                 data = self.data
 411.                 for k, v in environ.items():
 412.                     data[k.upper()] = v
 413.             def __setitem__(self, key, item):
 414.                 putenv(key, item)
 415.                 self.data[key.upper()] = item
 416.             def __getitem__(self, key):
 417.                 return self.data[key.upper()]
 418.             try:
 419.                 unsetenv
 420.             except NameError:
 421.                 def __delitem__(self, key):
 422.                     del self.data[key.upper()]
 423.             else:
 424.                 def __delitem__(self, key):
 425.                     unsetenv(key)
 426.                     del self.data[key.upper()]
 427.             def has_key(self, key):
 428.                 return key.upper() in self.data
 429.             def __contains__(self, key):
 430.                 return key.upper() in self.data
 431.             def get(self, key, failobj=None):
 432.                 return self.data.get(key.upper(), failobj)
 433.             def update(self, dict):
 434.                 for k, v in dict.items():
 435.                     self[k] = v
 436.             def copy(self):
 437.                 return dict(self)
 438. 
 439.     else:  # Where Env Var Names Can Be Mixed Case
 440.         class _Environ(UserDict.IterableUserDict):
 441.             def __init__(self, environ):
 442.                 UserDict.UserDict.__init__(self)
 443.                 self.data = environ
 444.             def __setitem__(self, key, item):
 445.                 putenv(key, item)
 446.                 self.data[key] = item
 447.             def update(self, dict):
 448.                 for k, v in dict.items():
 449.                     self[k] = v
 450.             try:
 451.                 unsetenv
 452.             except NameError:
 453.                 pass
 454.             else:
 455.                 def __delitem__(self, key):
 456.                     unsetenv(key)
 457.                     del self.data[key]
 458.             def copy(self):
 459.                 return dict(self)
 460. 
 461. 
 462.     environ = _Environ(environ)
 463. 
 464. def getenv(key, default=None):
 465.     """Get an environment variable, return None if it doesn't exist.
 466.     The optional second argument can specify an alternate default."""
 467.     return environ.get(key, default)
 468. __all__.append("getenv")
 469. 
 470. def _exists(name):
 471.     try:
 472.         eval(name)
 473.         return True
 474.     except NameError:
 475.         return False
 476. 
 477. # Supply spawn*() (probably only for Unix)
 478. if _exists("fork") and not _exists("spawnv") and _exists("execv"):
 479. 
 480.     P_WAIT = 0
 481.     P_NOWAIT = P_NOWAITO = 1
 482. 
 483.     # XXX Should we support P_DETACH?  I suppose it could fork()**2
 484.     # and close the std I/O streams.  Also, P_OVERLAY is the same
 485.     # as execv*()?
 486. 
 487.     def _spawnvef(mode, file, args, env, func):
 488.         # Internal helper; func is the exec*() function to use
 489.         pid = fork()
 490.         if not pid:
 491.             # Child
 492.             try:
 493.                 if env is None:
 494.                     func(file, args)
 495.                 else:
 496.                     func(file, args, env)
 497.             except:
 498.                 _exit(127)
 499.         else:
 500.             # Parent
 501.             if mode == P_NOWAIT:
 502.                 return pid # Caller is responsible for waiting!
 503.             while 1:
 504.                 wpid, sts = waitpid(pid, 0)
 505.                 if WIFSTOPPED(sts):
 506.                     continue
 507.                 elif WIFSIGNALED(sts):
 508.                     return -WTERMSIG(sts)
 509.                 elif WIFEXITED(sts):
 510.                     return WEXITSTATUS(sts)
 511.                 else:
 512.                     raise error, "Not stopped, signaled or exited???"
 513. 
 514.     def spawnv(mode, file, args):
 515.         """spawnv(mode, file, args) -> integer
 516. 
 517. Execute file with arguments from args in a subprocess.
 518. If mode == P_NOWAIT return the pid of the process.
 519. If mode == P_WAIT return the process's exit code if it exits normally;
 520. otherwise return -SIG, where SIG is the signal that killed it. """
 521.         return _spawnvef(mode, file, args, None, execv)
 522. 
 523.     def spawnve(mode, file, args, env):
 524.         """spawnve(mode, file, args, env) -> integer
 525. 
 526. Execute file with arguments from args in a subprocess with the
 527. specified environment.
 528. If mode == P_NOWAIT return the pid of the process.
 529. If mode == P_WAIT return the process's exit code if it exits normally;
 530. otherwise return -SIG, where SIG is the signal that killed it. """
 531.         return _spawnvef(mode, file, args, env, execve)
 532. 
 533.     # Note: spawnvp[e] is't currently supported on Windows
 534. 
 535.     def spawnvp(mode, file, args):
 536.         """spawnvp(mode, file, args) -> integer
 537. 
 538. Execute file (which is looked for along $PATH) with arguments from
 539. args in a subprocess.
 540. If mode == P_NOWAIT return the pid of the process.
 541. If mode == P_WAIT return the process's exit code if it exits normally;
 542. otherwise return -SIG, where SIG is the signal that killed it. """
 543.         return _spawnvef(mode, file, args, None, execvp)
 544. 
 545.     def spawnvpe(mode, file, args, env):
 546.         """spawnvpe(mode, file, args, env) -> integer
 547. 
 548. Execute file (which is looked for along $PATH) with arguments from
 549. args in a subprocess with the supplied environment.
 550. If mode == P_NOWAIT return the pid of the process.
 551. If mode == P_WAIT return the process's exit code if it exits normally;
 552. otherwise return -SIG, where SIG is the signal that killed it. """
 553.         return _spawnvef(mode, file, args, env, execvpe)
 554. 
 555. if _exists("spawnv"):
 556.     # These aren't supplied by the basic Windows code
 557.     # but can be easily implemented in Python
 558. 
 559.     def spawnl(mode, file, *args):
 560.         """spawnl(mode, file, *args) -> integer
 561. 
 562. Execute file with arguments from args in a subprocess.
 563. If mode == P_NOWAIT return the pid of the process.
 564. If mode == P_WAIT return the process's exit code if it exits normally;
 565. otherwise return -SIG, where SIG is the signal that killed it. """
 566.         return spawnv(mode, file, args)
 567. 
 568.     def spawnle(mode, file, *args):
 569.         """spawnle(mode, file, *args, env) -> integer
 570. 
 571. Execute file with arguments from args in a subprocess with the
 572. supplied environment.
 573. If mode == P_NOWAIT return the pid of the process.
 574. If mode == P_WAIT return the process's exit code if it exits normally;
 575. otherwise return -SIG, where SIG is the signal that killed it. """
 576.         env = args[-1]
 577.         return spawnve(mode, file, args[:-1], env)
 578. 
 579. 
 580.     __all__.extend(["spawnv", "spawnve", "spawnl", "spawnle",])
 581. 
 582. 
 583. if _exists("spawnvp"):
 584.     # At the moment, Windows doesn't implement spawnvp[e],
 585.     # so it won't have spawnlp[e] either.
 586.     def spawnlp(mode, file, *args):
 587.         """spawnlp(mode, file, *args) -> integer
 588. 
 589. Execute file (which is looked for along $PATH) with arguments from
 590. args in a subprocess with the supplied environment.
 591. If mode == P_NOWAIT return the pid of the process.
 592. If mode == P_WAIT return the process's exit code if it exits normally;
 593. otherwise return -SIG, where SIG is the signal that killed it. """
 594.         return spawnvp(mode, file, args)
 595. 
 596.     def spawnlpe(mode, file, *args):
 597.         """spawnlpe(mode, file, *args, env) -> integer
 598. 
 599. Execute file (which is looked for along $PATH) with arguments from
 600. args in a subprocess with the supplied environment.
 601. If mode == P_NOWAIT return the pid of the process.
 602. If mode == P_WAIT return the process's exit code if it exits normally;
 603. otherwise return -SIG, where SIG is the signal that killed it. """
 604.         env = args[-1]
 605.         return spawnvpe(mode, file, args[:-1], env)
 606. 
 607. 
 608.     __all__.extend(["spawnvp", "spawnvpe", "spawnlp", "spawnlpe",])
 609. 
 610. 
 611. # Supply popen2 etc. (for Unix)
 612. if _exists("fork"):
 613.     if not _exists("popen2"):
 614.         def popen2(cmd, mode="t", bufsize=-1):
 615.             import popen2
 616.             stdout, stdin = popen2.popen2(cmd, bufsize)
 617.             return stdin, stdout
 618.         __all__.append("popen2")
 619. 
 620.     if not _exists("popen3"):
 621.         def popen3(cmd, mode="t", bufsize=-1):
 622.             import popen2
 623.             stdout, stdin, stderr = popen2.popen3(cmd, bufsize)
 624.             return stdin, stdout, stderr
 625.         __all__.append("popen3")
 626. 
 627.     if not _exists("popen4"):
 628.         def popen4(cmd, mode="t", bufsize=-1):
 629.             import popen2
 630.             stdout, stdin = popen2.popen4(cmd, bufsize)
 631.             return stdin, stdout
 632.         __all__.append("popen4")
 633. 
 634. import copy_reg as _copy_reg
 635. 
 636. def _make_stat_result(tup, dict):
 637.     return stat_result(tup, dict)
 638. 
 639. def _pickle_stat_result(sr):
 640.     (type, args) = sr.__reduce__()
 641.     return (_make_stat_result, args)
 642. 
 643. try:
 644.     _copy_reg.pickle(stat_result, _pickle_stat_result, _make_stat_result)
 645. except NameError: # stat_result may not exist
 646.     pass
 647. 
 648. def _make_statvfs_result(tup, dict):
 649.     return statvfs_result(tup, dict)
 650. 
 651. def _pickle_statvfs_result(sr):
 652.     (type, args) = sr.__reduce__()
 653.     return (_make_statvfs_result, args)
 654. 
 655. try:
 656.     _copy_reg.pickle(statvfs_result, _pickle_statvfs_result,
 657.                      _make_statvfs_result)
 658. except NameError: # statvfs_result may not exist
 659.     pass