r"""OS routines for Mac, NT, or Posix depending on what system we're on.This exports: - all functions from posix, nt, os2, mac, or ce, e.g. unlink, stat, etc. - os.path is one of the modules posixpath, ntpath, or macpath - os.name is 'posix', 'nt', 'os2', 'mac', 'ce' or 'riscos' - os.curdir is a string representing the current directory ('.' or ':') - os.pardir is a string representing the parent directory ('..' or '::') - os.sep is the (or a most common) pathname separator ('/' or ':' or '\\') - os.extsep is the extension separator ('.' or '/') - os.altsep is the alternate pathname separator (None or '/') - os.pathsep is the component separator used in $PATH etc - os.linesep is the line separator in text files ('\r' or '\n' or '\r\n') - os.defpath is the default search path for executables - os.devnull is the file path of the null device ('/dev/null', etc.)Programs that import and use 'os' stand a better chance of beingportable between different platforms. Of course, they must thenonly use functions that are defined by all platforms (e.g., unlinkand opendir), and leave all pathname manipulation to os.path(e.g., split and join)."""#'import sys, errno_names = sys.builtin_module_names# Note: more names are added to __all__ later.__all__ = ["altsep", "curdir", "pardir", "sep", "pathsep", "linesep", "defpath", "name", "path", "devnull", "SEEK_SET", "SEEK_CUR", "SEEK_END"]def _get_exports_list(module): try: return list(module.__all__) except AttributeError: return [n for n in dir(module) if n[0] != '_']if 'posix' in _names: name = 'posix' linesep = '\n' from posix import * try: from posix import _exit except ImportError: pass import posixpath as path import posix __all__.extend(_get_exports_list(posix)) del posixelif 'nt' in _names: name = 'nt' linesep = '\r\n' from nt import * try: from nt import _exit except ImportError: pass import ntpath as path import nt __all__.extend(_get_exports_list(nt)) del ntelif 'os2' in _names: name = 'os2' linesep = '\r\n' from os2 import * try: from os2 import _exit except ImportError: pass if sys.version.find('EMX GCC') == -1: import ntpath as path else: import os2emxpath as path from _emx_link import link import os2 __all__.extend(_get_exports_list(os2)) del os2elif 'mac' in _names: name = 'mac' linesep = '\r' from mac import * try: from mac import _exit except ImportError: pass import macpath as path import mac __all__.extend(_get_exports_list(mac)) del macelif 'ce' in _names: name = 'ce' linesep = '\r\n' from ce import * try: from ce import _exit except ImportError: pass # We can use the standard Windows path. import ntpath as path import ce __all__.extend(_get_exports_list(ce)) del ceelif 'riscos' in _names: name = 'riscos' linesep = '\n' from riscos import * try: from riscos import _exit except ImportError: pass import riscospath as path import riscos __all__.extend(_get_exports_list(riscos)) del riscoselse: raise ImportError, 'no os specific module found'sys.modules['os.path'] = pathfrom os.path import (curdir, pardir, sep, pathsep, defpath, extsep, altsep, devnull)del _names# Python uses fixed values for the SEEK_ constants; they are mapped# to native constants if necessary in posixmodule.cSEEK_SET = 0SEEK_CUR = 1SEEK_END = 2#'# Super directory utilities.# (Inspired by Eric Raymond; the doc strings are mostly his)def makedirs(name, mode=0777): """makedirs(path [, mode=0777]) Super-mkdir; create a leaf directory and all intermediate ones. Works like mkdir, except that any intermediate path segment (not just the rightmost) will be created if it does not exist. This is recursive. """ head, tail = path.split(name) if not tail: head, tail = path.split(head) if head and tail and not path.exists(head): try: makedirs(head, mode) except OSError, e: # be happy if someone already created the path if e.errno != errno.EEXIST: raise if tail == curdir: # xxx/newdir/. exists if xxx/newdir exists return mkdir(name, mode)def removedirs(name): """removedirs(path) Super-rmdir; remove a leaf directory and all empty intermediate ones. Works like rmdir except that, if the leaf directory is successfully removed, directories corresponding to rightmost path segments will be pruned away until either the whole path is consumed or an error occurs. Errors during this latter phase are ignored -- they generally mean that a directory was not empty. """ rmdir(name) head, tail = path.split(name) if not tail: head, tail = path.split(head) while head and tail: try: rmdir(head) except error: break head, tail = path.split(head)def renames(old, new): """renames(old, new) Super-rename; create directories as necessary and delete any left empty. Works like rename, except creation of any intermediate directories needed to make the new pathname good is attempted first. After the rename, directories corresponding to rightmost path segments of the old name will be pruned way until either the whole path is consumed or a nonempty directory is found. Note: this function can fail with the new directory structure made if you lack permissions needed to unlink the leaf directory or file. """ head, tail = path.split(new) if head and tail and not path.exists(head): makedirs(head) rename(old, new) head, tail = path.split(old) if head and tail: try: removedirs(head) except error: pass__all__.extend(["makedirs", "removedirs", "renames"])def walk(top, topdown=True, onerror=None): """Directory tree generator. For each directory in the directory tree rooted at top (including top itself, but excluding '.' and '..'), yields a 3-tuple dirpath, dirnames, filenames dirpath is a string, the path to the directory. dirnames is a list of the names of the subdirectories in dirpath (excluding '.' and '..'). filenames is a list of the names of the non-directory files in dirpath. Note that the names in the lists are just names, with no path components. To get a full path (which begins with top) to a file or directory in dirpath, do os.path.join(dirpath, name). If optional arg 'topdown' is true or not specified, the triple for a directory is generated before the triples for any of its subdirectories (directories are generated top down). If topdown is false, the triple for a directory is generated after the triples for all of its subdirectories (directories are generated bottom up). When topdown is true, the caller can modify the dirnames list in-place (e.g., via del or slice assignment), and walk will only recurse into the subdirectories whose names remain in dirnames; this can be used to prune the search, or to impose a specific order of visiting. Modifying dirnames when topdown is false is ineffective, since the directories in dirnames have already been generated by the time dirnames itself is generated. By default errors from the os.listdir() call are ignored. If optional arg 'onerror' is specified, it should be a function; it will be called with one argument, an os.error instance. It can report the error to continue with the walk, or raise the exception to abort the walk. Note that the filename is available as the filename attribute of the exception object. Caution: if you pass a relative pathname for top, don't change the current working directory between resumptions of walk. walk never changes the current directory, and assumes that the client doesn't either. Example: from os.path import join, getsize for root, dirs, files in walk('python/Lib/email'): print root, "consumes", print sum([getsize(join(root, name)) for name in files]), print "bytes in", len(files), "non-directory files" if 'CVS' in dirs: dirs.remove('CVS') # don't visit CVS directories """ from os.path import join, isdir, islink # We may not have read permission for top, in which case we can't # get a list of the files the directory contains. os.path.walk # always suppressed the exception then, rather than blow up for a # minor reason when (say) a thousand readable directories are still # left to visit. That logic is copied here. try: # Note that listdir and error are globals in this module due # to earlier import-*. names = listdir(top) except error, err: if onerror is not None: onerror(err) return dirs, nondirs = [], [] for name in names: if isdir(join(top, name)): dirs.append(name) else: nondirs.append(name) if topdown: yield top, dirs, nondirs for name in dirs: path = join(top, name) if not islink(path): for x in walk(path, topdown, onerror): yield x if not topdown: yield top, dirs, nondirs__all__.append("walk")# Make sure os.environ exists, at leasttry: environexcept NameError: environ = {}def execl(file, *args): """execl(file, *args) Execute the executable file with argument list args, replacing the current process. """ execv(file, args)def execle(file, *args): """execle(file, *args, env) Execute the executable file with argument list args and environment env, replacing the current process. """ env = args[-1] execve(file, args[:-1], env)def execlp(file, *args): """execlp(file, *args) Execute the executable file (which is searched for along $PATH) with argument list args, replacing the current process. """ execvp(file, args)def execlpe(file, *args): """execlpe(file, *args, env) Execute the executable file (which is searched for along $PATH) with argument list args and environment env, replacing the current process. """ env = args[-1] execvpe(file, args[:-1], env)def execvp(file, args): """execp(file, args) Execute the executable file (which is searched for along $PATH) with argument list args, replacing the current process. args may be a list or tuple of strings. """ _execvpe(file, args)def execvpe(file, args, env): """execvpe(file, args, env) Execute the executable file (which is searched for along $PATH) with argument list args and environment env , replacing the current process. args may be a list or tuple of strings. """ _execvpe(file, args, env)__all__.extend(["execl","execle","execlp","execlpe","execvp","execvpe"])def _execvpe(file, args, env=None): if env is not None: func = execve argrest = (args, env) else: func = execv argrest = (args,) env = environ head, tail = path.split(file) if head: func(file, *argrest) return if 'PATH' in env: envpath = env['PATH'] else: envpath = defpath PATH = envpath.split(pathsep) saved_exc = None saved_tb = None for dir in PATH: fullname = path.join(dir, file) try: func(fullname, *argrest) except error, e: tb = sys.exc_info()[2] if (e.errno != errno.ENOENT and e.errno != errno.ENOTDIR and saved_exc is None): saved_exc = e saved_tb = tb if saved_exc: raise error, saved_exc, saved_tb raise error, e, tb# Change environ to automatically call putenv() if it existstry: # This will fail if there's no putenv putenvexcept NameError: passelse: import UserDict # Fake unsetenv() for Windows # not sure about os2 here but # I'm guessing they are the same. if name in ('os2', 'nt'): def unsetenv(key): putenv(key, "") if name == "riscos": # On RISC OS, all env access goes through getenv and putenv from riscosenviron import _Environ elif name in ('os2', 'nt'): # Where Env Var Names Must Be UPPERCASE # But we store them as upper case class _Environ(UserDict.IterableUserDict): def __init__(self, environ): UserDict.UserDict.__init__(self) data = self.data for k, v in environ.items(): data[k.upper()] = v def __setitem__(self, key, item): putenv(key, item) self.data[key.upper()] = item def __getitem__(self, key): return self.data[key.upper()] try: unsetenv except NameError: def __delitem__(self, key): del self.data[key.upper()] else: def __delitem__(self, key): unsetenv(key) del self.data[key.upper()] def has_key(self, key): return key.upper() in self.data def __contains__(self, key): return key.upper() in self.data def get(self, key, failobj=None): return self.data.get(key.upper(), failobj) def update(self, dict=None, **kwargs): if dict: try: keys = dict.keys() except AttributeError: # List of (key, value) for k, v in dict: self[k] = v else: # got keys # cannot use items(), since mappings # may not have them. for k in keys: self[k] = dict[k] if kwargs: self.update(kwargs) def copy(self): return dict(self) else: # Where Env Var Names Can Be Mixed Case class _Environ(UserDict.IterableUserDict): def __init__(self, environ): UserDict.UserDict.__init__(self) self.data = environ def __setitem__(self, key, item): putenv(key, item) self.data[key] = item def update(self, dict=None, **kwargs): if dict: try: keys = dict.keys() except AttributeError: # List of (key, value) for k, v in dict: self[k] = v else: # got keys # cannot use items(), since mappings # may not have them. for k in keys: self[k] = dict[k] if kwargs: self.update(kwargs) try: unsetenv except NameError: pass else: def __delitem__(self, key): unsetenv(key) del self.data[key] def copy(self): return dict(self) environ = _Environ(environ)def getenv(key, default=None): """Get an environment variable, return None if it doesn't exist. The optional second argument can specify an alternate default.""" return environ.get(key, default)__all__.append("getenv")def _exists(name): try: eval(name) return True except NameError: return False# Supply spawn*() (probably only for Unix)if _exists("fork") and not _exists("spawnv") and _exists("execv"): P_WAIT = 0 P_NOWAIT = P_NOWAITO = 1 # XXX Should we support P_DETACH? I suppose it could fork()**2 # and close the std I/O streams. Also, P_OVERLAY is the same # as execv*()? def _spawnvef(mode, file, args, env, func): # Internal helper; func is the exec*() function to use pid = fork() if not pid: # Child try: if env is None: func(file, args) else: func(file, args, env) except: _exit(127) else: # Parent if mode == P_NOWAIT: return pid # Caller is responsible for waiting! while 1: wpid, sts = waitpid(pid, 0) if WIFSTOPPED(sts): continue elif WIFSIGNALED(sts): return -WTERMSIG(sts) elif WIFEXITED(sts): return WEXITSTATUS(sts) else: raise error, "Not stopped, signaled or exited???" def spawnv(mode, file, args): """spawnv(mode, file, args) -> integerExecute file with arguments from args in a subprocess.If mode == P_NOWAIT return the pid of the process.If mode == P_WAIT return the process's exit code if it exits normally;otherwise return -SIG, where SIG is the signal that killed it. """ return _spawnvef(mode, file, args, None, execv) def spawnve(mode, file, args, env): """spawnve(mode, file, args, env) -> integerExecute file with arguments from args in a subprocess with thespecified environment.If mode == P_NOWAIT return the pid of the process.If mode == P_WAIT return the process's exit code if it exits normally;otherwise return -SIG, where SIG is the signal that killed it. """ return _spawnvef(mode, file, args, env, execve) # Note: spawnvp[e] is't currently supported on Windows def spawnvp(mode, file, args): """spawnvp(mode, file, args) -> integerExecute file (which is looked for along $PATH) with arguments fromargs in a subprocess.If mode == P_NOWAIT return the pid of the process.If mode == P_WAIT return the process's exit code if it exits normally;otherwise return -SIG, where SIG is the signal that killed it. """ return _spawnvef(mode, file, args, None, execvp) def spawnvpe(mode, file, args, env): """spawnvpe(mode, file, args, env) -> integerExecute file (which is looked for along $PATH) with arguments fromargs in a subprocess with the supplied environment.If mode == P_NOWAIT return the pid of the process.If mode == P_WAIT return the process's exit code if it exits normally;otherwise return -SIG, where SIG is the signal that killed it. """ return _spawnvef(mode, file, args, env, execvpe)if _exists("spawnv"): # These aren't supplied by the basic Windows code # but can be easily implemented in Python def spawnl(mode, file, *args): """spawnl(mode, file, *args) -> integerExecute file with arguments from args in a subprocess.If mode == P_NOWAIT return the pid of the process.If mode == P_WAIT return the process's exit code if it exits normally;otherwise return -SIG, where SIG is the signal that killed it. """ return spawnv(mode, file, args) def spawnle(mode, file, *args): """spawnle(mode, file, *args, env) -> integerExecute file with arguments from args in a subprocess with thesupplied environment.If mode == P_NOWAIT return the pid of the process.If mode == P_WAIT return the process's exit code if it exits normally;otherwise return -SIG, where SIG is the signal that killed it. """ env = args[-1] return spawnve(mode, file, args[:-1], env) __all__.extend(["spawnv", "spawnve", "spawnl", "spawnle",])if _exists("spawnvp"): # At the moment, Windows doesn't implement spawnvp[e], # so it won't have spawnlp[e] either. def spawnlp(mode, file, *args): """spawnlp(mode, file, *args) -> integerExecute file (which is looked for along $PATH) with arguments fromargs in a subprocess with the supplied environment.If mode == P_NOWAIT return the pid of the process.If mode == P_WAIT return the process's exit code if it exits normally;otherwise return -SIG, where SIG is the signal that killed it. """ return spawnvp(mode, file, args) def spawnlpe(mode, file, *args): """spawnlpe(mode, file, *args, env) -> integerExecute file (which is looked for along $PATH) with arguments fromargs in a subprocess with the supplied environment.If mode == P_NOWAIT return the pid of the process.If mode == P_WAIT return the process's exit code if it exits normally;otherwise return -SIG, where SIG is the signal that killed it. """ env = args[-1] return spawnvpe(mode, file, args[:-1], env) __all__.extend(["spawnvp", "spawnvpe", "spawnlp", "spawnlpe",])# Supply popen2 etc. (for Unix)if _exists("fork"): if not _exists("popen2"): def popen2(cmd, mode="t", bufsize=-1): """Execute the shell command 'cmd' in a sub-process. On UNIX, 'cmd' may be a sequence, in which case arguments will be passed directly to the program without shell intervention (as with os.spawnv()). If 'cmd' is a string it will be passed to the shell (as with os.system()). If 'bufsize' is specified, it sets the buffer size for the I/O pipes. The file objects (child_stdin, child_stdout) are returned.""" import popen2 stdout, stdin = popen2.popen2(cmd, bufsize) return stdin, stdout __all__.append("popen2") if not _exists("popen3"): def popen3(cmd, mode="t", bufsize=-1): """Execute the shell command 'cmd' in a sub-process. On UNIX, 'cmd' may be a sequence, in which case arguments will be passed directly to the program without shell intervention (as with os.spawnv()). If 'cmd' is a string it will be passed to the shell (as with os.system()). If 'bufsize' is specified, it sets the buffer size for the I/O pipes. The file objects (child_stdin, child_stdout, child_stderr) are returned.""" import popen2 stdout, stdin, stderr = popen2.popen3(cmd, bufsize) return stdin, stdout, stderr __all__.append("popen3") if not _exists("popen4"): def popen4(cmd, mode="t", bufsize=-1): """Execute the shell command 'cmd' in a sub-process. On UNIX, 'cmd' may be a sequence, in which case arguments will be passed directly to the program without shell intervention (as with os.spawnv()). If 'cmd' is a string it will be passed to the shell (as with os.system()). If 'bufsize' is specified, it sets the buffer size for the I/O pipes. The file objects (child_stdin, child_stdout_stderr) are returned.""" import popen2 stdout, stdin = popen2.popen4(cmd, bufsize) return stdin, stdout __all__.append("popen4")import copy_reg as _copy_regdef _make_stat_result(tup, dict): return stat_result(tup, dict)def _pickle_stat_result(sr): (type, args) = sr.__reduce__() return (_make_stat_result, args)try: _copy_reg.pickle(stat_result, _pickle_stat_result, _make_stat_result)except NameError: # stat_result may not exist passdef _make_statvfs_result(tup, dict): return statvfs_result(tup, dict)def _pickle_statvfs_result(sr): (type, args) = sr.__reduce__() return (_make_statvfs_result, args)try: _copy_reg.pickle(statvfs_result, _pickle_statvfs_result, _make_statvfs_result)except NameError: # statvfs_result may not exist passif not _exists("urandom"): def urandom(n): """urandom(n) -> str Return a string of n random bytes suitable for cryptographic use. """ try: _urandomfd = open("/dev/urandom", O_RDONLY) except (OSError, IOError): raise NotImplementedError("/dev/urandom (or equivalent) not found") bytes = "" while len(bytes) < n: bytes += read(_urandomfd, n - len(bytes)) close(_urandomfd) return bytes