r
"""OS routines for Mac, DOS, NT, or Posix depending on what system we're on.
- 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 being
portable between different platforms. Of course, they must then
only use functions that are defined by all platforms (e.g., unlink
and opendir), and leave all pathname manipulation to os.path
_names
= sys
.builtin_module_names
# Note: more names are added to __all__ later.
__all__
= ["altsep", "curdir", "pardir", "sep", "pathsep", "linesep",
"defpath", "name", "path", "devnull"]
def _get_exports_list(module
):
return list(module
.__all
__)
return [n
for n
in dir(module
) if n
[0] != '_']
__all__
.extend(_get_exports_list(posix
))
__all__
.extend(_get_exports_list(nt
))
if sys
.version
.find('EMX GCC') == -1:
import os2emxpath
as path
from _emx_link
import link
__all__
.extend(_get_exports_list(os2
))
__all__
.extend(_get_exports_list(mac
))
# We can use the standard Windows path.
__all__
.extend(_get_exports_list(ce
))
import riscospath
as path
__all__
.extend(_get_exports_list(riscos
))
raise ImportError, 'no os specific module found'
sys
.modules
['os.path'] = path
from os
.path
import (curdir
, pardir
, sep
, pathsep
, defpath
, extsep
, altsep
,
# 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
head
, tail
= path
.split(name
)
head
, tail
= path
.split(head
)
if head
and tail
and not path
.exists(head
):
if tail
== curdir
: # xxx/newdir/. exists if xxx/newdir exists
Super-rmdir; remove a leaf directory and empty all 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.
head
, tail
= path
.split(name
)
head
, tail
= path
.split(head
)
head
, tail
= path
.split(head
)
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
head
, tail
= path
.split(new
)
if head
and tail
and not path
.exists(head
):
head
, tail
= path
.split(old
)
__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
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
from os.path import join, getsize
for root, dirs, files in walk('python/Lib/email'):
print sum([getsize(join(root, name)) for name in files]),
print "bytes in", len(files), "non-directory files"
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.
# Note that listdir and error are globals in this module due
if isdir(join(top
, name
)):
for x
in walk(path
, topdown
, onerror
):
# Make sure os.environ exists, at least
Execute the executable file with argument list args, replacing the
"""execle(file, *args, env)
Execute the executable file with argument list args and
environment env, replacing the current process. """
execve(file, args
[:-1], env
)
Execute the executable file (which is searched for along $PATH)
with argument list args, replacing the current process. """
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
execvpe(file, args
[:-1], env
)
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. """
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
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):
from errno
import ENOENT
, ENOTDIR
head
, tail
= path
.split(file)
PATH
= envpath
.split(pathsep
)
fullname
= path
.join(dir, file)
if (e
.errno
!= ENOENT
and e
.errno
!= ENOTDIR
raise error
, saved_exc
, saved_tb
# Change environ to automatically call putenv() if it exists
# This will fail if there's no putenv
# Fake unsetenv() for Windows
# not sure about os2 here but
# I'm guessing they are the same.
if name
in ('os2', 'nt'):
# 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
)
for k
, v
in environ
.items():
def __setitem__(self
, key
, item
):
self
.data
[key
.upper()] = item
def __getitem__(self
, key
):
return self
.data
[key
.upper()]
def __delitem__(self
, key
):
del self
.data
[key
.upper()]
def __delitem__(self
, key
):
del self
.data
[key
.upper()]
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
):
# cannot use items(), since mappings
else: # Where Env Var Names Can Be Mixed Case
class _Environ(UserDict
.IterableUserDict
):
def __init__(self
, environ
):
UserDict
.UserDict
.__init
__(self
)
def __setitem__(self
, key
, item
):
def update(self
, dict=None, **kwargs
):
# cannot use items(), since mappings
def __delitem__(self
, key
):
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
)
# Supply spawn*() (probably only for Unix)
if _exists("fork") and not _exists("spawnv") and _exists("execv"):
# 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
def _spawnvef(mode
, file, args
, env
, func
):
# Internal helper; func is the exec*() function to use
return pid
# Caller is responsible for waiting!
wpid
, sts
= waitpid(pid
, 0)
raise error
, "Not stopped, signaled or exited???"
def spawnv(mode
, file, args
):
"""spawnv(mode, file, args) -> integer
Execute 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) -> integer
Execute file with arguments from args in a subprocess with the
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) -> integer
Execute file (which is looked for along $PATH) with arguments from
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) -> integer
Execute file (which is looked for along $PATH) with arguments from
args 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
)
# 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) -> integer
Execute 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) -> integer
Execute file with arguments from args in a subprocess with the
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 spawnve(mode
, file, args
[:-1], env
)
__all__
.extend(["spawnv", "spawnve", "spawnl", "spawnle",])
# 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) -> integer
Execute file (which is looked for along $PATH) with arguments from
args 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) -> integer
Execute file (which is looked for along $PATH) with arguments from
args 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 spawnvpe(mode
, file, args
[:-1], env
)
__all__
.extend(["spawnvp", "spawnvpe", "spawnlp", "spawnlpe",])
# Supply popen2 etc. (for Unix)
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."""
stdout
, stdin
= popen2
.popen2(cmd
, bufsize
)
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."""
stdout
, stdin
, stderr
= popen2
.popen3(cmd
, bufsize
)
return stdin
, stdout
, stderr
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."""
stdout
, stdin
= popen2
.popen4(cmd
, bufsize
)
import copy_reg
as _copy_reg
def _make_stat_result(tup
, dict):
return stat_result(tup
, dict)
def _pickle_stat_result(sr
):
(type, args
) = sr
.__reduce
__()
return (_make_stat_result
, args
)
_copy_reg
.pickle(stat_result
, _pickle_stat_result
, _make_stat_result
)
except NameError: # stat_result may not exist
def _make_statvfs_result(tup
, dict):
return statvfs_result(tup
, dict)
def _pickle_statvfs_result(sr
):
(type, args
) = sr
.__reduce
__()
return (_make_statvfs_result
, args
)
_copy_reg
.pickle(statvfs_result
, _pickle_statvfs_result
,
except NameError: # statvfs_result may not exist
if not _exists("urandom"):
Return a string of n random bytes suitable for cryptographic use.
_urandomfd
= open("/dev/urandom", O_RDONLY
)
raise NotImplementedError("/dev/urandom (or equivalent) not found")
bytes
+= read(_urandomfd
, n
- len(bytes
))