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cpython/Lib/os.py

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r"""OS routines for NT or Posix depending on what system we're on.
This exports:
- all functions from posix or nt, e.g. unlink, stat, etc.
- os.path is either posixpath or ntpath
- os.name is either 'posix' or 'nt'
- os.curdir is a string representing the current directory (always '.')
- os.pardir is a string representing the parent directory (always '..')
- os.sep is the (or a most common) pathname separator ('/' or '\\')
- os.extsep is the extension separator (always '.')
- 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
(e.g., split and join).
"""
#'
import abc
import sys, errno
import stat as st
_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", "fsencode", "fsdecode", "get_exec_path", "fdopen",
"popen", "extsep"]
def _exists(name):
return name in globals()
def _get_exports_list(module):
try:
return list(module.__all__)
except AttributeError:
return [n for n in dir(module) if n[0] != '_']
# Any new dependencies of the os module and/or changes in path separator
# requires updating importlib as well.
if 'posix' in _names:
name = 'posix'
linesep = '\n'
from posix import *
try:
from posix import _exit
__all__.append('_exit')
except ImportError:
pass
import posixpath as path
try:
from posix import _have_functions
except ImportError:
pass
import posix
__all__.extend(_get_exports_list(posix))
del posix
elif 'nt' in _names:
name = 'nt'
linesep = '\r\n'
from nt import *
try:
from nt import _exit
__all__.append('_exit')
except ImportError:
pass
import ntpath as path
import nt
__all__.extend(_get_exports_list(nt))
del nt
try:
from nt import _have_functions
except ImportError:
pass
else:
raise ImportError('no os specific module found')
sys.modules['os.path'] = path
from os.path import (curdir, pardir, sep, pathsep, defpath, extsep, altsep,
devnull)
del _names
if _exists("_have_functions"):
_globals = globals()
def _add(str, fn):
if (fn in _globals) and (str in _have_functions):
_set.add(_globals[fn])
_set = set()
_add("HAVE_FACCESSAT", "access")
_add("HAVE_FCHMODAT", "chmod")
_add("HAVE_FCHOWNAT", "chown")
_add("HAVE_FSTATAT", "stat")
_add("HAVE_FUTIMESAT", "utime")
_add("HAVE_LINKAT", "link")
_add("HAVE_MKDIRAT", "mkdir")
_add("HAVE_MKFIFOAT", "mkfifo")
_add("HAVE_MKNODAT", "mknod")
_add("HAVE_OPENAT", "open")
_add("HAVE_READLINKAT", "readlink")
_add("HAVE_RENAMEAT", "rename")
_add("HAVE_SYMLINKAT", "symlink")
_add("HAVE_UNLINKAT", "unlink")
_add("HAVE_UNLINKAT", "rmdir")
_add("HAVE_UTIMENSAT", "utime")
supports_dir_fd = _set
_set = set()
_add("HAVE_FACCESSAT", "access")
supports_effective_ids = _set
_set = set()
_add("HAVE_FCHDIR", "chdir")
_add("HAVE_FCHMOD", "chmod")
_add("HAVE_FCHOWN", "chown")
_add("HAVE_FDOPENDIR", "listdir")
_add("HAVE_FEXECVE", "execve")
_set.add(stat) # fstat always works
_add("HAVE_FTRUNCATE", "truncate")
_add("HAVE_FUTIMENS", "utime")
_add("HAVE_FUTIMES", "utime")
_add("HAVE_FPATHCONF", "pathconf")
if _exists("statvfs") and _exists("fstatvfs"): # mac os x10.3
_add("HAVE_FSTATVFS", "statvfs")
supports_fd = _set
_set = set()
_add("HAVE_FACCESSAT", "access")
# Some platforms don't support lchmod(). Often the function exists
# anyway, as a stub that always returns ENOSUP or perhaps EOPNOTSUPP.
# (No, I don't know why that's a good design.) ./configure will detect
# this and reject it--so HAVE_LCHMOD still won't be defined on such
# platforms. This is Very Helpful.
#
# However, sometimes platforms without a working lchmod() *do* have
# fchmodat(). (Examples: Linux kernel 3.2 with glibc 2.15,
# OpenIndiana 3.x.) And fchmodat() has a flag that theoretically makes
# it behave like lchmod(). So in theory it would be a suitable
# replacement for lchmod(). But when lchmod() doesn't work, fchmodat()'s
# flag doesn't work *either*. Sadly ./configure isn't sophisticated
# enough to detect this condition--it only determines whether or not
# fchmodat() minimally works.
#
# Therefore we simply ignore fchmodat() when deciding whether or not
# os.chmod supports follow_symlinks. Just checking lchmod() is
# sufficient. After all--if you have a working fchmodat(), your
# lchmod() almost certainly works too.
#
# _add("HAVE_FCHMODAT", "chmod")
_add("HAVE_FCHOWNAT", "chown")
_add("HAVE_FSTATAT", "stat")
_add("HAVE_LCHFLAGS", "chflags")
_add("HAVE_LCHMOD", "chmod")
if _exists("lchown"): # mac os x10.3
_add("HAVE_LCHOWN", "chown")
_add("HAVE_LINKAT", "link")
_add("HAVE_LUTIMES", "utime")
_add("HAVE_LSTAT", "stat")
_add("HAVE_FSTATAT", "stat")
_add("HAVE_UTIMENSAT", "utime")
_add("MS_WINDOWS", "stat")
supports_follow_symlinks = _set
del _set
del _have_functions
del _globals
del _add
# Python uses fixed values for the SEEK_ constants; they are mapped
# to native constants if necessary in posixmodule.c
# Other possible SEEK values are directly imported from posixmodule.c
SEEK_SET = 0
SEEK_CUR = 1
SEEK_END = 2
# Super directory utilities.
# (Inspired by Eric Raymond; the doc strings are mostly his)
def makedirs(name, mode=0o777, exist_ok=False):
"""makedirs(name [, mode=0o777][, exist_ok=False])
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. If the target directory already
exists, raise an OSError if exist_ok is False. Otherwise no exception is
raised. 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, exist_ok)
except FileExistsError:
# Defeats race condition when another thread created the path
pass
cdir = curdir
if isinstance(tail, bytes):
cdir = bytes(curdir, 'ASCII')
if tail == cdir: # xxx/newdir/. exists if xxx/newdir exists
return
try:
mkdir(name, mode)
except OSError:
# Cannot rely on checking for EEXIST, since the operating system
# could give priority to other errors like EACCES or EROFS
if not exist_ok or not path.isdir(name):
raise
def removedirs(name):
"""removedirs(name)
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 OSError:
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 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 OSError:
pass
__all__.extend(["makedirs", "removedirs", "renames"])
def walk(top, topdown=True, onerror=None, followlinks=False):
"""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. No matter
the value of topdown, the list of subdirectories is retrieved before the
tuples for the directory and its subdirectories are generated.
By default errors from the os.scandir() call are ignored. If
optional arg 'onerror' is specified, it should be a function; it
will be called with one argument, an OSError 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.
By default, os.walk does not follow symbolic links to subdirectories on
systems that support them. In order to get this functionality, set the
optional argument 'followlinks' to true.
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:
import os
from os.path import join, getsize
for root, dirs, files in os.walk('python/Lib/email'):
print(root, "consumes", end="")
print(sum([getsize(join(root, name)) for name in files]), end="")
print("bytes in", len(files), "non-directory files")
if 'CVS' in dirs:
dirs.remove('CVS') # don't visit CVS directories
"""
top = fspath(top)
dirs = []
nondirs = []
walk_dirs = []
# We may not have read permission for top, in which case we can't
# get a list of the files the directory contains. os.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 scandir is global in this module due
# to earlier import-*.
scandir_it = scandir(top)
except OSError as error:
if onerror is not None:
onerror(error)
return
with scandir_it:
while True:
try:
try:
entry = next(scandir_it)
except StopIteration:
break
except OSError as error:
if onerror is not None:
onerror(error)
return
try:
is_dir = entry.is_dir()
except OSError:
# If is_dir() raises an OSError, consider that the entry is not
# a directory, same behaviour than os.path.isdir().
is_dir = False
if is_dir:
dirs.append(entry.name)
else:
nondirs.append(entry.name)
if not topdown and is_dir:
# Bottom-up: recurse into sub-directory, but exclude symlinks to
# directories if followlinks is False
if followlinks:
walk_into = True
else:
try:
is_symlink = entry.is_symlink()
except OSError:
# If is_symlink() raises an OSError, consider that the
# entry is not a symbolic link, same behaviour than
# os.path.islink().
is_symlink = False
walk_into = not is_symlink
if walk_into:
walk_dirs.append(entry.path)
# Yield before recursion if going top down
if topdown:
yield top, dirs, nondirs
# Recurse into sub-directories
islink, join = path.islink, path.join
for dirname in dirs:
new_path = join(top, dirname)
# Issue #23605: os.path.islink() is used instead of caching
# entry.is_symlink() result during the loop on os.scandir() because
# the caller can replace the directory entry during the "yield"
# above.
if followlinks or not islink(new_path):
yield from walk(new_path, topdown, onerror, followlinks)
else:
# Recurse into sub-directories
for new_path in walk_dirs:
yield from walk(new_path, topdown, onerror, followlinks)
# Yield after recursion if going bottom up
yield top, dirs, nondirs
__all__.append("walk")
if {open, stat} <= supports_dir_fd and {listdir, stat} <= supports_fd:
def fwalk(top=".", topdown=True, onerror=None, *, follow_symlinks=False, dir_fd=None):
"""Directory tree generator.
This behaves exactly like walk(), except that it yields a 4-tuple
dirpath, dirnames, filenames, dirfd
`dirpath`, `dirnames` and `filenames` are identical to walk() output,
and `dirfd` is a file descriptor referring to the directory `dirpath`.
The advantage of fwalk() over walk() is that it's safe against symlink
races (when follow_symlinks is False).
If dir_fd is not None, it should be a file descriptor open to a directory,
and top should be relative; top will then be relative to that directory.
(dir_fd is always supported for fwalk.)
Caution:
Since fwalk() yields file descriptors, those are only valid until the
next iteration step, so you should dup() them if you want to keep them
for a longer period.
Example:
import os
for root, dirs, files, rootfd in os.fwalk('python/Lib/email'):
print(root, "consumes", end="")
print(sum([os.stat(name, dir_fd=rootfd).st_size for name in files]),
end="")
print("bytes in", len(files), "non-directory files")
if 'CVS' in dirs:
dirs.remove('CVS') # don't visit CVS directories
"""
if not isinstance(top, int) or not hasattr(top, '__index__'):
top = fspath(top)
# Note: To guard against symlink races, we use the standard
# lstat()/open()/fstat() trick.
orig_st = stat(top, follow_symlinks=False, dir_fd=dir_fd)
topfd = open(top, O_RDONLY, dir_fd=dir_fd)
try:
if (follow_symlinks or (st.S_ISDIR(orig_st.st_mode) and
path.samestat(orig_st, stat(topfd)))):
yield from _fwalk(topfd, top, topdown, onerror, follow_symlinks)
finally:
close(topfd)
def _fwalk(topfd, toppath, topdown, onerror, follow_symlinks):
# Note: This uses O(depth of the directory tree) file descriptors: if
# necessary, it can be adapted to only require O(1) FDs, see issue
# #13734.
names = listdir(topfd)
dirs, nondirs = [], []
for name in names:
try:
# Here, we don't use AT_SYMLINK_NOFOLLOW to be consistent with
# walk() which reports symlinks to directories as directories.
# We do however check for symlinks before recursing into
# a subdirectory.
if st.S_ISDIR(stat(name, dir_fd=topfd).st_mode):
dirs.append(name)
else:
nondirs.append(name)
except FileNotFoundError:
try:
# Add dangling symlinks, ignore disappeared files
if st.S_ISLNK(stat(name, dir_fd=topfd, follow_symlinks=False)
.st_mode):
nondirs.append(name)
except FileNotFoundError:
continue
if topdown:
yield toppath, dirs, nondirs, topfd
for name in dirs:
try:
orig_st = stat(name, dir_fd=topfd, follow_symlinks=follow_symlinks)
dirfd = open(name, O_RDONLY, dir_fd=topfd)
except OSError as err:
if onerror is not None:
onerror(err)
continue
try:
if follow_symlinks or path.samestat(orig_st, stat(dirfd)):
dirpath = path.join(toppath, name)
yield from _fwalk(dirfd, dirpath, topdown, onerror, follow_symlinks)
finally:
close(dirfd)
if not topdown:
yield toppath, dirs, nondirs, topfd
__all__.append("fwalk")
# Make sure os.environ exists, at least
try:
environ
except 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):
"""execvp(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:
exec_func = execve
argrest = (args, env)
else:
exec_func = execv
argrest = (args,)
env = environ
head, tail = path.split(file)
if head:
exec_func(file, *argrest)
return
last_exc = saved_exc = None
saved_tb = None
path_list = get_exec_path(env)
if name != 'nt':
file = fsencode(file)
path_list = map(fsencode, path_list)
for dir in path_list:
fullname = path.join(dir, file)
try:
exec_func(fullname, *argrest)
except OSError as e:
last_exc = 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 saved_exc.with_traceback(saved_tb)
raise last_exc.with_traceback(tb)
def get_exec_path(env=None):
"""Returns the sequence of directories that will be searched for the
named executable (similar to a shell) when launching a process.
*env* must be an environment variable dict or None. If *env* is None,
os.environ will be used.
"""
# Use a local import instead of a global import to limit the number of
# modules loaded at startup: the os module is always loaded at startup by
# Python. It may also avoid a bootstrap issue.
import warnings
if env is None:
env = environ
# {b'PATH': ...}.get('PATH') and {'PATH': ...}.get(b'PATH') emit a
# BytesWarning when using python -b or python -bb: ignore the warning
with warnings.catch_warnings():
warnings.simplefilter("ignore", BytesWarning)
try:
path_list = env.get('PATH')
except TypeError:
path_list = None
if supports_bytes_environ:
try:
path_listb = env[b'PATH']
except (KeyError, TypeError):
pass
else:
if path_list is not None:
raise ValueError(
"env cannot contain 'PATH' and b'PATH' keys")
path_list = path_listb
if path_list is not None and isinstance(path_list, bytes):
path_list = fsdecode(path_list)
if path_list is None:
path_list = defpath
return path_list.split(pathsep)
# Change environ to automatically call putenv(), unsetenv if they exist.
from _collections_abc import MutableMapping
class _Environ(MutableMapping):
def __init__(self, data, encodekey, decodekey, encodevalue, decodevalue, putenv, unsetenv):
self.encodekey = encodekey
self.decodekey = decodekey
self.encodevalue = encodevalue
self.decodevalue = decodevalue
self.putenv = putenv
self.unsetenv = unsetenv
self._data = data
def __getitem__(self, key):
try:
value = self._data[self.encodekey(key)]
except KeyError:
# raise KeyError with the original key value
raise KeyError(key) from None
return self.decodevalue(value)
def __setitem__(self, key, value):
key = self.encodekey(key)
value = self.encodevalue(value)
self.putenv(key, value)
self._data[key] = value
def __delitem__(self, key):
encodedkey = self.encodekey(key)
self.unsetenv(encodedkey)
try:
del self._data[encodedkey]
except KeyError:
# raise KeyError with the original key value
raise KeyError(key) from None
def __iter__(self):
for key in self._data:
yield self.decodekey(key)
def __len__(self):
return len(self._data)
def __repr__(self):
return 'environ({{{}}})'.format(', '.join(
('{!r}: {!r}'.format(self.decodekey(key), self.decodevalue(value))
for key, value in self._data.items())))
def copy(self):
return dict(self)
def setdefault(self, key, value):
if key not in self:
self[key] = value
return self[key]
try:
_putenv = putenv
except NameError:
_putenv = lambda key, value: None
else:
if "putenv" not in __all__:
__all__.append("putenv")
try:
_unsetenv = unsetenv
except NameError:
_unsetenv = lambda key: _putenv(key, "")
else:
if "unsetenv" not in __all__:
__all__.append("unsetenv")
def _createenviron():
if name == 'nt':
# Where Env Var Names Must Be UPPERCASE
def check_str(value):
if not isinstance(value, str):
raise TypeError("str expected, not %s" % type(value).__name__)
return value
encode = check_str
decode = str
def encodekey(key):
return encode(key).upper()
data = {}
for key, value in environ.items():
data[encodekey(key)] = value
else:
# Where Env Var Names Can Be Mixed Case
encoding = sys.getfilesystemencoding()
def encode(value):
if not isinstance(value, str):
raise TypeError("str expected, not %s" % type(value).__name__)
return value.encode(encoding, 'surrogateescape')
def decode(value):
return value.decode(encoding, 'surrogateescape')
encodekey = encode
data = environ
return _Environ(data,
encodekey, decode,
encode, decode,
_putenv, _unsetenv)
# unicode environ
environ = _createenviron()
del _createenviron
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.
key, default and the result are str."""
return environ.get(key, default)
supports_bytes_environ = (name != 'nt')
__all__.extend(("getenv", "supports_bytes_environ"))
if supports_bytes_environ:
def _check_bytes(value):
if not isinstance(value, bytes):
raise TypeError("bytes expected, not %s" % type(value).__name__)
return value
# bytes environ
environb = _Environ(environ._data,
_check_bytes, bytes,
_check_bytes, bytes,
_putenv, _unsetenv)
del _check_bytes
def getenvb(key, default=None):
"""Get an environment variable, return None if it doesn't exist.
The optional second argument can specify an alternate default.
key, default and the result are bytes."""
return environb.get(key, default)
__all__.extend(("environb", "getenvb"))
def _fscodec():
encoding = sys.getfilesystemencoding()
errors = sys.getfilesystemencodeerrors()
def fsencode(filename):
"""Encode filename (an os.PathLike, bytes, or str) to the filesystem
encoding with 'surrogateescape' error handler, return bytes unchanged.
On Windows, use 'strict' error handler if the file system encoding is
'mbcs' (which is the default encoding).
"""
filename = fspath(filename) # Does type-checking of `filename`.
if isinstance(filename, str):
return filename.encode(encoding, errors)
else:
return filename
def fsdecode(filename):
"""Decode filename (an os.PathLike, bytes, or str) from the filesystem
encoding with 'surrogateescape' error handler, return str unchanged. On
Windows, use 'strict' error handler if the file system encoding is
'mbcs' (which is the default encoding).
"""
filename = fspath(filename) # Does type-checking of `filename`.
if isinstance(filename, bytes):
return filename.decode(encoding, errors)
else:
return filename
return fsencode, fsdecode
fsencode, fsdecode = _fscodec()
del _fscodec
# Supply spawn*() (probably only for Unix)
if _exists("fork") and not _exists("spawnv") and _exists("execv"):
P_WAIT = 0
P_NOWAIT = P_NOWAITO = 1
__all__.extend(["P_WAIT", "P_NOWAIT", "P_NOWAITO"])
# 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 OSError("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
specified 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) -> integer
Execute file (which is looked for along $PATH) 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, 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)
__all__.extend(["spawnv", "spawnve", "spawnvp", "spawnvpe"])
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) -> 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
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 spawnve(mode, file, args[:-1], env)
__all__.extend(["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) -> 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. """
env = args[-1]
return spawnvpe(mode, file, args[:-1], env)
__all__.extend(["spawnlp", "spawnlpe"])
# Supply os.popen()
def popen(cmd, mode="r", buffering=-1):
if not isinstance(cmd, str):
raise TypeError("invalid cmd type (%s, expected string)" % type(cmd))
if mode not in ("r", "w"):
raise ValueError("invalid mode %r" % mode)
if buffering == 0 or buffering is None:
raise ValueError("popen() does not support unbuffered streams")
import subprocess, io
if mode == "r":
proc = subprocess.Popen(cmd,
shell=True,
stdout=subprocess.PIPE,
bufsize=buffering)
return _wrap_close(io.TextIOWrapper(proc.stdout), proc)
else:
proc = subprocess.Popen(cmd,
shell=True,
stdin=subprocess.PIPE,
bufsize=buffering)
return _wrap_close(io.TextIOWrapper(proc.stdin), proc)
# Helper for popen() -- a proxy for a file whose close waits for the process
class _wrap_close:
def __init__(self, stream, proc):
self._stream = stream
self._proc = proc
def close(self):
self._stream.close()
returncode = self._proc.wait()
if returncode == 0:
return None
if name == 'nt':
return returncode
else:
return returncode << 8 # Shift left to match old behavior
def __enter__(self):
return self
def __exit__(self, *args):
self.close()
def __getattr__(self, name):
return getattr(self._stream, name)
def __iter__(self):
return iter(self._stream)
# Supply os.fdopen()
def fdopen(fd, *args, **kwargs):
if not isinstance(fd, int):
raise TypeError("invalid fd type (%s, expected integer)" % type(fd))
import io
return io.open(fd, *args, **kwargs)
# For testing purposes, make sure the function is available when the C
# implementation exists.
def _fspath(path):
"""Return the path representation of a path-like object.
If str or bytes is passed in, it is returned unchanged. Otherwise the
os.PathLike interface is used to get the path representation. If the
path representation is not str or bytes, TypeError is raised. If the
provided path is not str, bytes, or os.PathLike, TypeError is raised.
"""
if isinstance(path, (str, bytes)):
return path
# Work from the object's type to match method resolution of other magic
# methods.
path_type = type(path)
try:
path_repr = path_type.__fspath__(path)
except AttributeError:
if hasattr(path_type, '__fspath__'):
raise
else:
raise TypeError("expected str, bytes or os.PathLike object, "
"not " + path_type.__name__)
if isinstance(path_repr, (str, bytes)):
return path_repr
else:
raise TypeError("expected {}.__fspath__() to return str or bytes, "
"not {}".format(path_type.__name__,
type(path_repr).__name__))
# If there is no C implementation, make the pure Python version the
# implementation as transparently as possible.
if not _exists('fspath'):
fspath = _fspath
fspath.__name__ = "fspath"
class PathLike(abc.ABC):
"""Abstract base class for implementing the file system path protocol."""
@abc.abstractmethod
def __fspath__(self):
"""Return the file system path representation of the object."""
raise NotImplementedError
@classmethod
def __subclasshook__(cls, subclass):
return hasattr(subclass, '__fspath__')
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