[mirror_edk2.git] / AppPkg / Applications / Python / PyMod-2.7.2 / Lib / os.py

"""OS routines for Mac, NT, Posix, or UEFI depending on what system we're on.\r
\r
This exports:\r
  - all functions from edk2, posix, nt, os2, or ce, e.g. unlink, stat, etc.\r
  - os.path is one of the modules uefipath, posixpath, or ntpath\r
  - os.name is 'edk2', 'posix', 'nt', 'os2', 'ce' or 'riscos'\r
  - os.curdir is a string representing the current directory ('.' or ':')\r
  - os.pardir is a string representing the parent directory ('..' or '::')\r
  - os.sep is the (or a most common) pathname separator ('/' or ':' or '\\')\r
  - os.extsep is the extension separator ('.' or '/')\r
  - os.altsep is the alternate pathname separator (None or '/')\r
  - os.pathsep is the component separator used in $PATH etc\r
  - os.linesep is the line separator in text files ('\r' or '\n' or '\r\n')\r
  - os.defpath is the default search path for executables\r
  - os.devnull is the file path of the null device ('/dev/null', etc.)\r
\r
Programs that import and use 'os' stand a better chance of being\r
portable between different platforms.  Of course, they must then\r
only use functions that are defined by all platforms (e.g., unlink\r
and opendir), and leave all pathname manipulation to os.path\r
(e.g., split and join).\r
"""\r
\r
#'\r
\r
import sys, errno\r
\r
_names = sys.builtin_module_names\r
\r
# Note:  more names are added to __all__ later.\r
__all__ = ["altsep", "curdir", "pardir", "sep", "extsep", "pathsep", "linesep",\r
           "defpath", "name", "path", "devnull",\r
           "SEEK_SET", "SEEK_CUR", "SEEK_END"]\r
\r
def _get_exports_list(module):\r
    try:\r
        return list(module.__all__)\r
    except AttributeError:\r
        return [n for n in dir(module) if n[0] != '_']\r
\r
if 'posix' in _names:\r
    name = 'posix'\r
    linesep = '\n'\r
    from posix import *\r
    try:\r
        from posix import _exit\r
    except ImportError:\r
        pass\r
    import posixpath as path\r
\r
    import posix\r
    __all__.extend(_get_exports_list(posix))\r
    del posix\r
\r
elif 'nt' in _names:\r
    name = 'nt'\r
    linesep = '\r\n'\r
    from nt import *\r
    try:\r
        from nt import _exit\r
    except ImportError:\r
        pass\r
    import ntpath as path\r
\r
    import nt\r
    __all__.extend(_get_exports_list(nt))\r
    del nt\r
\r
elif 'os2' in _names:\r
    name = 'os2'\r
    linesep = '\r\n'\r
    from os2 import *\r
    try:\r
        from os2 import _exit\r
    except ImportError:\r
        pass\r
    if sys.version.find('EMX GCC') == -1:\r
        import ntpath as path\r
    else:\r
        import os2emxpath as path\r
        from _emx_link import link\r
\r
    import os2\r
    __all__.extend(_get_exports_list(os2))\r
    del os2\r
\r
elif 'ce' in _names:\r
    name = 'ce'\r
    linesep = '\r\n'\r
    from ce import *\r
    try:\r
        from ce import _exit\r
    except ImportError:\r
        pass\r
    # We can use the standard Windows path.\r
    import ntpath as path\r
\r
    import ce\r
    __all__.extend(_get_exports_list(ce))\r
    del ce\r
\r
elif 'riscos' in _names:\r
    name = 'riscos'\r
    linesep = '\n'\r
    from riscos import *\r
    try:\r
        from riscos import _exit\r
    except ImportError:\r
        pass\r
    import riscospath as path\r
\r
    import riscos\r
    __all__.extend(_get_exports_list(riscos))\r
    del riscos\r
\r
elif 'edk2' in _names:\r
    name = 'edk2'\r
    linesep = '\n'\r
    from edk2 import *\r
    try:\r
        from edk2 import _exit\r
    except ImportError:\r
        pass\r
    import ntpath as path\r
\r
    import edk2\r
    __all__.extend(_get_exports_list(edk2))\r
    del edk2\r
\r
else:\r
    raise ImportError, 'no os specific module found'\r
\r
sys.modules['os.path'] = path\r
from os.path import (curdir, pardir, sep, pathsep, defpath, extsep, altsep,\r
    devnull)\r
\r
del _names\r
\r
# Python uses fixed values for the SEEK_ constants; they are mapped\r
# to native constants if necessary in posixmodule.c\r
SEEK_SET = 0\r
SEEK_CUR = 1\r
SEEK_END = 2\r
\r
#'\r
\r
# Super directory utilities.\r
# (Inspired by Eric Raymond; the doc strings are mostly his)\r
\r
def makedirs(name, mode=0777):\r
    """makedirs(path [, mode=0777])\r
\r
    Super-mkdir; create a leaf directory and all intermediate ones.\r
    Works like mkdir, except that any intermediate path segment (not\r
    just the rightmost) will be created if it does not exist.  This is\r
    recursive.\r
\r
    """\r
    head, tail = path.split(name)\r
    if not tail:\r
        head, tail = path.split(head)\r
    if head and tail and not path.exists(head):\r
        try:\r
            makedirs(head, mode)\r
        except OSError, e:\r
            # be happy if someone already created the path\r
            if e.errno != errno.EEXIST:\r
                raise\r
        if tail == curdir:           # xxx/newdir/. exists if xxx/newdir exists\r
            return\r
    mkdir(name, mode)\r
\r
def removedirs(name):\r
    """removedirs(path)\r
\r
    Super-rmdir; remove a leaf directory and all empty intermediate\r
    ones.  Works like rmdir except that, if the leaf directory is\r
    successfully removed, directories corresponding to rightmost path\r
    segments will be pruned away until either the whole path is\r
    consumed or an error occurs.  Errors during this latter phase are\r
    ignored -- they generally mean that a directory was not empty.\r
\r
    """\r
    rmdir(name)\r
    head, tail = path.split(name)\r
    if not tail:\r
        head, tail = path.split(head)\r
    while head and tail:\r
        try:\r
            rmdir(head)\r
        except error:\r
            break\r
        head, tail = path.split(head)\r
\r
def renames(old, new):\r
    """renames(old, new)\r
\r
    Super-rename; create directories as necessary and delete any left\r
    empty.  Works like rename, except creation of any intermediate\r
    directories needed to make the new pathname good is attempted\r
    first.  After the rename, directories corresponding to rightmost\r
    path segments of the old name will be pruned way until either the\r
    whole path is consumed or a nonempty directory is found.\r
\r
    Note: this function can fail with the new directory structure made\r
    if you lack permissions needed to unlink the leaf directory or\r
    file.\r
\r
    """\r
    head, tail = path.split(new)\r
    if head and tail and not path.exists(head):\r
        makedirs(head)\r
    rename(old, new)\r
    head, tail = path.split(old)\r
    if head and tail:\r
        try:\r
            removedirs(head)\r
        except error:\r
            pass\r
\r
__all__.extend(["makedirs", "removedirs", "renames"])\r
\r
def walk(top, topdown=True, onerror=None, followlinks=False):\r
    """Directory tree generator.\r
\r
    For each directory in the directory tree rooted at top (including top\r
    itself, but excluding '.' and '..'), yields a 3-tuple\r
\r
        dirpath, dirnames, filenames\r
\r
    dirpath is a string, the path to the directory.  dirnames is a list of\r
    the names of the subdirectories in dirpath (excluding '.' and '..').\r
    filenames is a list of the names of the non-directory files in dirpath.\r
    Note that the names in the lists are just names, with no path components.\r
    To get a full path (which begins with top) to a file or directory in\r
    dirpath, do os.path.join(dirpath, name).\r
\r
    If optional arg 'topdown' is true or not specified, the triple for a\r
    directory is generated before the triples for any of its subdirectories\r
    (directories are generated top down).  If topdown is false, the triple\r
    for a directory is generated after the triples for all of its\r
    subdirectories (directories are generated bottom up).\r
\r
    When topdown is true, the caller can modify the dirnames list in-place\r
    (e.g., via del or slice assignment), and walk will only recurse into the\r
    subdirectories whose names remain in dirnames; this can be used to prune\r
    the search, or to impose a specific order of visiting.  Modifying\r
    dirnames when topdown is false is ineffective, since the directories in\r
    dirnames have already been generated by the time dirnames itself is\r
    generated.\r
\r
    By default errors from the os.listdir() call are ignored.  If\r
    optional arg 'onerror' is specified, it should be a function; it\r
    will be called with one argument, an os.error instance.  It can\r
    report the error to continue with the walk, or raise the exception\r
    to abort the walk.  Note that the filename is available as the\r
    filename attribute of the exception object.\r
\r
    By default, os.walk does not follow symbolic links to subdirectories on\r
    systems that support them.  In order to get this functionality, set the\r
    optional argument 'followlinks' to true.\r
\r
    Caution:  if you pass a relative pathname for top, don't change the\r
    current working directory between resumptions of walk.  walk never\r
    changes the current directory, and assumes that the client doesn't\r
    either.\r
\r
    Example:\r
\r
    import os\r
    from os.path import join, getsize\r
    for root, dirs, files in os.walk('python/Lib/email'):\r
        print root, "consumes",\r
        print sum([getsize(join(root, name)) for name in files]),\r
        print "bytes in", len(files), "non-directory files"\r
        if 'CVS' in dirs:\r
            dirs.remove('CVS')  # don't visit CVS directories\r
    """\r
\r
    islink, join, isdir = path.islink, path.join, path.isdir\r
\r
    # We may not have read permission for top, in which case we can't\r
    # get a list of the files the directory contains.  os.path.walk\r
    # always suppressed the exception then, rather than blow up for a\r
    # minor reason when (say) a thousand readable directories are still\r
    # left to visit.  That logic is copied here.\r
    try:\r
        # Note that listdir and error are globals in this module due\r
        # to earlier import-*.\r
        names = listdir(top)\r
    except error, err:\r
        if onerror is not None:\r
            onerror(err)\r
        return\r
\r
    dirs, nondirs = [], []\r
    for name in names:\r
        if isdir(join(top, name)):\r
            dirs.append(name)\r
        else:\r
            nondirs.append(name)\r
\r
    if topdown:\r
        yield top, dirs, nondirs\r
    for name in dirs:\r
        new_path = join(top, name)\r
        if followlinks or not islink(new_path):\r
            for x in walk(new_path, topdown, onerror, followlinks):\r
                yield x\r
    if not topdown:\r
        yield top, dirs, nondirs\r
\r
__all__.append("walk")\r
\r
# Make sure os.environ exists, at least\r
try:\r
    environ\r
except NameError:\r
    environ = {}\r
\r
def execl(file, *args):\r
    """execl(file, *args)\r
\r
    Execute the executable file with argument list args, replacing the\r
    current process. """\r
    execv(file, args)\r
\r
def execle(file, *args):\r
    """execle(file, *args, env)\r
\r
    Execute the executable file with argument list args and\r
    environment env, replacing the current process. """\r
    env = args[-1]\r
    execve(file, args[:-1], env)\r
\r
def execlp(file, *args):\r
    """execlp(file, *args)\r
\r
    Execute the executable file (which is searched for along $PATH)\r
    with argument list args, replacing the current process. """\r
    execvp(file, args)\r
\r
def execlpe(file, *args):\r
    """execlpe(file, *args, env)\r
\r
    Execute the executable file (which is searched for along $PATH)\r
    with argument list args and environment env, replacing the current\r
    process. """\r
    env = args[-1]\r
    execvpe(file, args[:-1], env)\r
\r
def execvp(file, args):\r
    """execvp(file, args)\r
\r
    Execute the executable file (which is searched for along $PATH)\r
    with argument list args, replacing the current process.\r
    args may be a list or tuple of strings. """\r
    _execvpe(file, args)\r
\r
def execvpe(file, args, env):\r
    """execvpe(file, args, env)\r
\r
    Execute the executable file (which is searched for along $PATH)\r
    with argument list args and environment env , replacing the\r
    current process.\r
    args may be a list or tuple of strings. """\r
    _execvpe(file, args, env)\r
\r
__all__.extend(["execl","execle","execlp","execlpe","execvp","execvpe"])\r
\r
def _execvpe(file, args, env=None):\r
    if env is not None:\r
        func = execve\r
        argrest = (args, env)\r
    else:\r
        func = execv\r
        argrest = (args,)\r
        env = environ\r
\r
    head, tail = path.split(file)\r
    if head:\r
        func(file, *argrest)\r
        return\r
    if 'PATH' in env:\r
        envpath = env['PATH']\r
    else:\r
        envpath = defpath\r
    PATH = envpath.split(pathsep)\r
    saved_exc = None\r
    saved_tb = None\r
    for dir in PATH:\r
        fullname = path.join(dir, file)\r
        try:\r
            func(fullname, *argrest)\r
        except error, e:\r
            tb = sys.exc_info()[2]\r
            if (e.errno != errno.ENOENT and e.errno != errno.ENOTDIR\r
                and saved_exc is None):\r
                saved_exc = e\r
                saved_tb = tb\r
    if saved_exc:\r
        raise error, saved_exc, saved_tb\r
    raise error, e, tb\r
\r
# Change environ to automatically call putenv() if it exists\r
try:\r
    # This will fail if there's no putenv\r
    putenv\r
except NameError:\r
    pass\r
else:\r
    import UserDict\r
\r
    # Fake unsetenv() for Windows\r
    # not sure about os2 here but\r
    # I'm guessing they are the same.\r
\r
    if name in ('os2', 'nt'):\r
        def unsetenv(key):\r
            putenv(key, "")\r
\r
    if name == "riscos":\r
        # On RISC OS, all env access goes through getenv and putenv\r
        from riscosenviron import _Environ\r
    elif name in ('os2', 'nt'):  # Where Env Var Names Must Be UPPERCASE\r
        # But we store them as upper case\r
        class _Environ(UserDict.IterableUserDict):\r
            def __init__(self, environ):\r
                UserDict.UserDict.__init__(self)\r
                data = self.data\r
                for k, v in environ.items():\r
                    data[k.upper()] = v\r
            def __setitem__(self, key, item):\r
                putenv(key, item)\r
                self.data[key.upper()] = item\r
            def __getitem__(self, key):\r
                return self.data[key.upper()]\r
            try:\r
                unsetenv\r
            except NameError:\r
                def __delitem__(self, key):\r
                    del self.data[key.upper()]\r
            else:\r
                def __delitem__(self, key):\r
                    unsetenv(key)\r
                    del self.data[key.upper()]\r
                def clear(self):\r
                    for key in self.data.keys():\r
                        unsetenv(key)\r
                        del self.data[key]\r
                def pop(self, key, *args):\r
                    unsetenv(key)\r
                    return self.data.pop(key.upper(), *args)\r
            def has_key(self, key):\r
                return key.upper() in self.data\r
            def __contains__(self, key):\r
                return key.upper() in self.data\r
            def get(self, key, failobj=None):\r
                return self.data.get(key.upper(), failobj)\r
            def update(self, dict=None, **kwargs):\r
                if dict:\r
                    try:\r
                        keys = dict.keys()\r
                    except AttributeError:\r
                        # List of (key, value)\r
                        for k, v in dict:\r
                            self[k] = v\r
                    else:\r
                        # got keys\r
                        # cannot use items(), since mappings\r
                        # may not have them.\r
                        for k in keys:\r
                            self[k] = dict[k]\r
                if kwargs:\r
                    self.update(kwargs)\r
            def copy(self):\r
                return dict(self)\r
\r
    else:  # Where Env Var Names Can Be Mixed Case\r
        class _Environ(UserDict.IterableUserDict):\r
            def __init__(self, environ):\r
                UserDict.UserDict.__init__(self)\r
                self.data = environ\r
            def __setitem__(self, key, item):\r
                putenv(key, item)\r
                self.data[key] = item\r
            def update(self,  dict=None, **kwargs):\r
                if dict:\r
                    try:\r
                        keys = dict.keys()\r
                    except AttributeError:\r
                        # List of (key, value)\r
                        for k, v in dict:\r
                            self[k] = v\r
                    else:\r
                        # got keys\r
                        # cannot use items(), since mappings\r
                        # may not have them.\r
                        for k in keys:\r
                            self[k] = dict[k]\r
                if kwargs:\r
                    self.update(kwargs)\r
            try:\r
                unsetenv\r
            except NameError:\r
                pass\r
            else:\r
                def __delitem__(self, key):\r
                    unsetenv(key)\r
                    del self.data[key]\r
                def clear(self):\r
                    for key in self.data.keys():\r
                        unsetenv(key)\r
                        del self.data[key]\r
                def pop(self, key, *args):\r
                    unsetenv(key)\r
                    return self.data.pop(key, *args)\r
            def copy(self):\r
                return dict(self)\r
\r
\r
    environ = _Environ(environ)\r
\r
def getenv(key, default=None):\r
    """Get an environment variable, return None if it doesn't exist.\r
    The optional second argument can specify an alternate default."""\r
    return environ.get(key, default)\r
__all__.append("getenv")\r
\r
def _exists(name):\r
    return name in globals()\r
\r
# Supply spawn*() (probably only for Unix)\r
if _exists("fork") and not _exists("spawnv") and _exists("execv"):\r
\r
    P_WAIT = 0\r
    P_NOWAIT = P_NOWAITO = 1\r
\r
    # XXX Should we support P_DETACH?  I suppose it could fork()**2\r
    # and close the std I/O streams.  Also, P_OVERLAY is the same\r
    # as execv*()?\r
\r
    def _spawnvef(mode, file, args, env, func):\r
        # Internal helper; func is the exec*() function to use\r
        pid = fork()\r
        if not pid:\r
            # Child\r
            try:\r
                if env is None:\r
                    func(file, args)\r
                else:\r
                    func(file, args, env)\r
            except:\r
                _exit(127)\r
        else:\r
            # Parent\r
            if mode == P_NOWAIT:\r
                return pid # Caller is responsible for waiting!\r
            while 1:\r
                wpid, sts = waitpid(pid, 0)\r
                if WIFSTOPPED(sts):\r
                    continue\r
                elif WIFSIGNALED(sts):\r
                    return -WTERMSIG(sts)\r
                elif WIFEXITED(sts):\r
                    return WEXITSTATUS(sts)\r
                else:\r
                    raise error, "Not stopped, signaled or exited???"\r
\r
    def spawnv(mode, file, args):\r
        """spawnv(mode, file, args) -> integer\r
\r
Execute file with arguments from args in a subprocess.\r
If mode == P_NOWAIT return the pid of the process.\r
If mode == P_WAIT return the process's exit code if it exits normally;\r
otherwise return -SIG, where SIG is the signal that killed it. """\r
        return _spawnvef(mode, file, args, None, execv)\r
\r
    def spawnve(mode, file, args, env):\r
        """spawnve(mode, file, args, env) -> integer\r
\r
Execute file with arguments from args in a subprocess with the\r
specified environment.\r
If mode == P_NOWAIT return the pid of the process.\r
If mode == P_WAIT return the process's exit code if it exits normally;\r
otherwise return -SIG, where SIG is the signal that killed it. """\r
        return _spawnvef(mode, file, args, env, execve)\r
\r
    # Note: spawnvp[e] is't currently supported on Windows\r
\r
    def spawnvp(mode, file, args):\r
        """spawnvp(mode, file, args) -> integer\r
\r
Execute file (which is looked for along $PATH) with arguments from\r
args in a subprocess.\r
If mode == P_NOWAIT return the pid of the process.\r
If mode == P_WAIT return the process's exit code if it exits normally;\r
otherwise return -SIG, where SIG is the signal that killed it. """\r
        return _spawnvef(mode, file, args, None, execvp)\r
\r
    def spawnvpe(mode, file, args, env):\r
        """spawnvpe(mode, file, args, env) -> integer\r
\r
Execute file (which is looked for along $PATH) with arguments from\r
args in a subprocess with the supplied environment.\r
If mode == P_NOWAIT return the pid of the process.\r
If mode == P_WAIT return the process's exit code if it exits normally;\r
otherwise return -SIG, where SIG is the signal that killed it. """\r
        return _spawnvef(mode, file, args, env, execvpe)\r
\r
if _exists("spawnv"):\r
    # These aren't supplied by the basic Windows code\r
    # but can be easily implemented in Python\r
\r
    def spawnl(mode, file, *args):\r
        """spawnl(mode, file, *args) -> integer\r
\r
Execute file with arguments from args in a subprocess.\r
If mode == P_NOWAIT return the pid of the process.\r
If mode == P_WAIT return the process's exit code if it exits normally;\r
otherwise return -SIG, where SIG is the signal that killed it. """\r
        return spawnv(mode, file, args)\r
\r
    def spawnle(mode, file, *args):\r
        """spawnle(mode, file, *args, env) -> integer\r
\r
Execute file with arguments from args in a subprocess with the\r
supplied environment.\r
If mode == P_NOWAIT return the pid of the process.\r
If mode == P_WAIT return the process's exit code if it exits normally;\r
otherwise return -SIG, where SIG is the signal that killed it. """\r
        env = args[-1]\r
        return spawnve(mode, file, args[:-1], env)\r
\r
\r
    __all__.extend(["spawnv", "spawnve", "spawnl", "spawnle",])\r
\r
\r
if _exists("spawnvp"):\r
    # At the moment, Windows doesn't implement spawnvp[e],\r
    # so it won't have spawnlp[e] either.\r
    def spawnlp(mode, file, *args):\r
        """spawnlp(mode, file, *args) -> integer\r
\r
Execute file (which is looked for along $PATH) with arguments from\r
args in a subprocess with the supplied environment.\r
If mode == P_NOWAIT return the pid of the process.\r
If mode == P_WAIT return the process's exit code if it exits normally;\r
otherwise return -SIG, where SIG is the signal that killed it. """\r
        return spawnvp(mode, file, args)\r
\r
    def spawnlpe(mode, file, *args):\r
        """spawnlpe(mode, file, *args, env) -> integer\r
\r
Execute file (which is looked for along $PATH) with arguments from\r
args in a subprocess with the supplied environment.\r
If mode == P_NOWAIT return the pid of the process.\r
If mode == P_WAIT return the process's exit code if it exits normally;\r
otherwise return -SIG, where SIG is the signal that killed it. """\r
        env = args[-1]\r
        return spawnvpe(mode, file, args[:-1], env)\r
\r
\r
    __all__.extend(["spawnvp", "spawnvpe", "spawnlp", "spawnlpe",])\r
\r
\r
# Supply popen2 etc. (for Unix)\r
if _exists("fork"):\r
    if not _exists("popen2"):\r
        def popen2(cmd, mode="t", bufsize=-1):\r
            """Execute the shell command 'cmd' in a sub-process.  On UNIX, 'cmd'\r
            may be a sequence, in which case arguments will be passed directly to\r
            the program without shell intervention (as with os.spawnv()).  If 'cmd'\r
            is a string it will be passed to the shell (as with os.system()). If\r
            'bufsize' is specified, it sets the buffer size for the I/O pipes.  The\r
            file objects (child_stdin, child_stdout) are returned."""\r
            import warnings\r
            msg = "os.popen2 is deprecated.  Use the subprocess module."\r
            warnings.warn(msg, DeprecationWarning, stacklevel=2)\r
\r
            import subprocess\r
            PIPE = subprocess.PIPE\r
            p = subprocess.Popen(cmd, shell=isinstance(cmd, basestring),\r
                                 bufsize=bufsize, stdin=PIPE, stdout=PIPE,\r
                                 close_fds=True)\r
            return p.stdin, p.stdout\r
        __all__.append("popen2")\r
\r
    if not _exists("popen3"):\r
        def popen3(cmd, mode="t", bufsize=-1):\r
            """Execute the shell command 'cmd' in a sub-process.  On UNIX, 'cmd'\r
            may be a sequence, in which case arguments will be passed directly to\r
            the program without shell intervention (as with os.spawnv()).  If 'cmd'\r
            is a string it will be passed to the shell (as with os.system()). If\r
            'bufsize' is specified, it sets the buffer size for the I/O pipes.  The\r
            file objects (child_stdin, child_stdout, child_stderr) are returned."""\r
            import warnings\r
            msg = "os.popen3 is deprecated.  Use the subprocess module."\r
            warnings.warn(msg, DeprecationWarning, stacklevel=2)\r
\r
            import subprocess\r
            PIPE = subprocess.PIPE\r
            p = subprocess.Popen(cmd, shell=isinstance(cmd, basestring),\r
                                 bufsize=bufsize, stdin=PIPE, stdout=PIPE,\r
                                 stderr=PIPE, close_fds=True)\r
            return p.stdin, p.stdout, p.stderr\r
        __all__.append("popen3")\r
\r
    if not _exists("popen4"):\r
        def popen4(cmd, mode="t", bufsize=-1):\r
            """Execute the shell command 'cmd' in a sub-process.  On UNIX, 'cmd'\r
            may be a sequence, in which case arguments will be passed directly to\r
            the program without shell intervention (as with os.spawnv()).  If 'cmd'\r
            is a string it will be passed to the shell (as with os.system()). If\r
            'bufsize' is specified, it sets the buffer size for the I/O pipes.  The\r
            file objects (child_stdin, child_stdout_stderr) are returned."""\r
            import warnings\r
            msg = "os.popen4 is deprecated.  Use the subprocess module."\r
            warnings.warn(msg, DeprecationWarning, stacklevel=2)\r
\r
            import subprocess\r
            PIPE = subprocess.PIPE\r
            p = subprocess.Popen(cmd, shell=isinstance(cmd, basestring),\r
                                 bufsize=bufsize, stdin=PIPE, stdout=PIPE,\r
                                 stderr=subprocess.STDOUT, close_fds=True)\r
            return p.stdin, p.stdout\r
        __all__.append("popen4")\r
\r
import copy_reg as _copy_reg\r
\r
def _make_stat_result(tup, dict):\r
    return stat_result(tup, dict)\r
\r
def _pickle_stat_result(sr):\r
    (type, args) = sr.__reduce__()\r
    return (_make_stat_result, args)\r
\r
try:\r
    _copy_reg.pickle(stat_result, _pickle_stat_result, _make_stat_result)\r
except NameError: # stat_result may not exist\r
    pass\r
\r
def _make_statvfs_result(tup, dict):\r
    return statvfs_result(tup, dict)\r
\r
def _pickle_statvfs_result(sr):\r
    (type, args) = sr.__reduce__()\r
    return (_make_statvfs_result, args)\r
\r
try:\r
    _copy_reg.pickle(statvfs_result, _pickle_statvfs_result,\r
                     _make_statvfs_result)\r
except NameError: # statvfs_result may not exist\r
    pass\r
\r
if not _exists("urandom"):\r
    def urandom(n):\r
        """urandom(n) -> str\r
\r
        Return a string of n random bytes suitable for cryptographic use.\r
\r
        """\r
        try:\r
            _urandomfd = open("/dev/urandom", O_RDONLY)\r
        except (OSError, IOError):\r
            raise NotImplementedError("/dev/urandom (or equivalent) not found")\r
        try:\r
            bs = b""\r
            while n > len(bs):\r
                bs += read(_urandomfd, n - len(bs))\r
        finally:\r
            close(_urandomfd)\r
        return bs\r