Mini Shell
# encoding: utf-8
"""
Utilities for path handling.
"""
# Copyright (c) IPython Development Team.
# Distributed under the terms of the Modified BSD License.
import os
import sys
import errno
import shutil
import random
import glob
from IPython.utils.process import system
#-----------------------------------------------------------------------------
# Code
#-----------------------------------------------------------------------------
fs_encoding = sys.getfilesystemencoding()
def _writable_dir(path):
"""Whether `path` is a directory, to which the user has write access."""
return os.path.isdir(path) and os.access(path, os.W_OK)
if sys.platform == 'win32':
def _get_long_path_name(path):
"""Get a long path name (expand ~) on Windows using ctypes.
Examples
--------
>>> get_long_path_name('c:\\\\docume~1')
'c:\\\\Documents and Settings'
"""
try:
import ctypes
except ImportError as e:
raise ImportError('you need to have ctypes installed for this to work') from e
_GetLongPathName = ctypes.windll.kernel32.GetLongPathNameW
_GetLongPathName.argtypes = [ctypes.c_wchar_p, ctypes.c_wchar_p,
ctypes.c_uint ]
buf = ctypes.create_unicode_buffer(260)
rv = _GetLongPathName(path, buf, 260)
if rv == 0 or rv > 260:
return path
else:
return buf.value
else:
def _get_long_path_name(path):
"""Dummy no-op."""
return path
def get_long_path_name(path):
"""Expand a path into its long form.
On Windows this expands any ~ in the paths. On other platforms, it is
a null operation.
"""
return _get_long_path_name(path)
def compress_user(path):
"""Reverse of :func:`os.path.expanduser`
"""
home = os.path.expanduser('~')
if path.startswith(home):
path = "~" + path[len(home):]
return path
def get_py_filename(name):
"""Return a valid python filename in the current directory.
If the given name is not a file, it adds '.py' and searches again.
Raises IOError with an informative message if the file isn't found.
"""
name = os.path.expanduser(name)
if os.path.isfile(name):
return name
if not name.endswith(".py"):
py_name = name + ".py"
if os.path.isfile(py_name):
return py_name
raise IOError("File `%r` not found." % name)
def filefind(filename: str, path_dirs=None) -> str:
"""Find a file by looking through a sequence of paths.
This iterates through a sequence of paths looking for a file and returns
the full, absolute path of the first occurrence of the file. If no set of
path dirs is given, the filename is tested as is, after running through
:func:`expandvars` and :func:`expanduser`. Thus a simple call::
filefind('myfile.txt')
will find the file in the current working dir, but::
filefind('~/myfile.txt')
Will find the file in the users home directory. This function does not
automatically try any paths, such as the cwd or the user's home directory.
Parameters
----------
filename : str
The filename to look for.
path_dirs : str, None or sequence of str
The sequence of paths to look for the file in. If None, the filename
need to be absolute or be in the cwd. If a string, the string is
put into a sequence and the searched. If a sequence, walk through
each element and join with ``filename``, calling :func:`expandvars`
and :func:`expanduser` before testing for existence.
Returns
-------
path : str
returns absolute path to file.
Raises
------
IOError
"""
# If paths are quoted, abspath gets confused, strip them...
filename = filename.strip('"').strip("'")
# If the input is an absolute path, just check it exists
if os.path.isabs(filename) and os.path.isfile(filename):
return filename
if path_dirs is None:
path_dirs = ("",)
elif isinstance(path_dirs, str):
path_dirs = (path_dirs,)
for path in path_dirs:
if path == '.': path = os.getcwd()
testname = expand_path(os.path.join(path, filename))
if os.path.isfile(testname):
return os.path.abspath(testname)
raise IOError("File %r does not exist in any of the search paths: %r" %
(filename, path_dirs) )
class HomeDirError(Exception):
pass
def get_home_dir(require_writable=False) -> str:
"""Return the 'home' directory, as a unicode string.
Uses os.path.expanduser('~'), and checks for writability.
See stdlib docs for how this is determined.
For Python <3.8, $HOME is first priority on *ALL* platforms.
For Python >=3.8 on Windows, %HOME% is no longer considered.
Parameters
----------
require_writable : bool [default: False]
if True:
guarantees the return value is a writable directory, otherwise
raises HomeDirError
if False:
The path is resolved, but it is not guaranteed to exist or be writable.
"""
homedir = os.path.expanduser('~')
# Next line will make things work even when /home/ is a symlink to
# /usr/home as it is on FreeBSD, for example
homedir = os.path.realpath(homedir)
if not _writable_dir(homedir) and os.name == 'nt':
# expanduser failed, use the registry to get the 'My Documents' folder.
try:
import winreg as wreg
with wreg.OpenKey(
wreg.HKEY_CURRENT_USER,
r"Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders"
) as key:
homedir = wreg.QueryValueEx(key,'Personal')[0]
except:
pass
if (not require_writable) or _writable_dir(homedir):
assert isinstance(homedir, str), "Homedir should be unicode not bytes"
return homedir
else:
raise HomeDirError('%s is not a writable dir, '
'set $HOME environment variable to override' % homedir)
def get_xdg_dir():
"""Return the XDG_CONFIG_HOME, if it is defined and exists, else None.
This is only for non-OS X posix (Linux,Unix,etc.) systems.
"""
env = os.environ
if os.name == "posix":
# Linux, Unix, AIX, etc.
# use ~/.config if empty OR not set
xdg = env.get("XDG_CONFIG_HOME", None) or os.path.join(get_home_dir(), '.config')
if xdg and _writable_dir(xdg):
assert isinstance(xdg, str)
return xdg
return None
def get_xdg_cache_dir():
"""Return the XDG_CACHE_HOME, if it is defined and exists, else None.
This is only for non-OS X posix (Linux,Unix,etc.) systems.
"""
env = os.environ
if os.name == "posix":
# Linux, Unix, AIX, etc.
# use ~/.cache if empty OR not set
xdg = env.get("XDG_CACHE_HOME", None) or os.path.join(get_home_dir(), '.cache')
if xdg and _writable_dir(xdg):
assert isinstance(xdg, str)
return xdg
return None
def expand_path(s):
"""Expand $VARS and ~names in a string, like a shell
:Examples:
In [2]: os.environ['FOO']='test'
In [3]: expand_path('variable FOO is $FOO')
Out[3]: 'variable FOO is test'
"""
# This is a pretty subtle hack. When expand user is given a UNC path
# on Windows (\\server\share$\%username%), os.path.expandvars, removes
# the $ to get (\\server\share\%username%). I think it considered $
# alone an empty var. But, we need the $ to remains there (it indicates
# a hidden share).
if os.name=='nt':
s = s.replace('$\\', 'IPYTHON_TEMP')
s = os.path.expandvars(os.path.expanduser(s))
if os.name=='nt':
s = s.replace('IPYTHON_TEMP', '$\\')
return s
def unescape_glob(string):
"""Unescape glob pattern in `string`."""
def unescape(s):
for pattern in '*[]!?':
s = s.replace(r'\{0}'.format(pattern), pattern)
return s
return '\\'.join(map(unescape, string.split('\\\\')))
def shellglob(args):
"""
Do glob expansion for each element in `args` and return a flattened list.
Unmatched glob pattern will remain as-is in the returned list.
"""
expanded = []
# Do not unescape backslash in Windows as it is interpreted as
# path separator:
unescape = unescape_glob if sys.platform != 'win32' else lambda x: x
for a in args:
expanded.extend(glob.glob(a) or [unescape(a)])
return expanded
def target_outdated(target,deps):
"""Determine whether a target is out of date.
target_outdated(target,deps) -> 1/0
deps: list of filenames which MUST exist.
target: single filename which may or may not exist.
If target doesn't exist or is older than any file listed in deps, return
true, otherwise return false.
"""
try:
target_time = os.path.getmtime(target)
except os.error:
return 1
for dep in deps:
dep_time = os.path.getmtime(dep)
if dep_time > target_time:
#print "For target",target,"Dep failed:",dep # dbg
#print "times (dep,tar):",dep_time,target_time # dbg
return 1
return 0
def target_update(target,deps,cmd):
"""Update a target with a given command given a list of dependencies.
target_update(target,deps,cmd) -> runs cmd if target is outdated.
This is just a wrapper around target_outdated() which calls the given
command if target is outdated."""
if target_outdated(target,deps):
system(cmd)
ENOLINK = 1998
def link(src, dst):
"""Hard links ``src`` to ``dst``, returning 0 or errno.
Note that the special errno ``ENOLINK`` will be returned if ``os.link`` isn't
supported by the operating system.
"""
if not hasattr(os, "link"):
return ENOLINK
link_errno = 0
try:
os.link(src, dst)
except OSError as e:
link_errno = e.errno
return link_errno
def link_or_copy(src, dst):
"""Attempts to hardlink ``src`` to ``dst``, copying if the link fails.
Attempts to maintain the semantics of ``shutil.copy``.
Because ``os.link`` does not overwrite files, a unique temporary file
will be used if the target already exists, then that file will be moved
into place.
"""
if os.path.isdir(dst):
dst = os.path.join(dst, os.path.basename(src))
link_errno = link(src, dst)
if link_errno == errno.EEXIST:
if os.stat(src).st_ino == os.stat(dst).st_ino:
# dst is already a hard link to the correct file, so we don't need
# to do anything else. If we try to link and rename the file
# anyway, we get duplicate files - see http://bugs.python.org/issue21876
return
new_dst = dst + "-temp-%04X" %(random.randint(1, 16**4), )
try:
link_or_copy(src, new_dst)
except:
try:
os.remove(new_dst)
except OSError:
pass
raise
os.rename(new_dst, dst)
elif link_errno != 0:
# Either link isn't supported, or the filesystem doesn't support
# linking, or 'src' and 'dst' are on different filesystems.
shutil.copy(src, dst)
def ensure_dir_exists(path, mode=0o755):
"""ensure that a directory exists
If it doesn't exist, try to create it and protect against a race condition
if another process is doing the same.
The default permissions are 755, which differ from os.makedirs default of 777.
"""
if not os.path.exists(path):
try:
os.makedirs(path, mode=mode)
except OSError as e:
if e.errno != errno.EEXIST:
raise
elif not os.path.isdir(path):
raise IOError("%r exists but is not a directory" % path)
Zerion Mini Shell 1.0