mirror of
https://github.com/codeninjasllc/codecombat.git
synced 2024-11-29 18:45:48 -05:00
66 lines
2.3 KiB
Python
66 lines
2.3 KiB
Python
|
__author__ = 'root'
|
||
|
#copied from python3
|
||
|
import os
|
||
|
import sys
|
||
|
|
||
|
def which(cmd, mode=os.F_OK | os.X_OK, path=None):
|
||
|
"""Given a command, mode, and a PATH string, return the path which
|
||
|
conforms to the given mode on the PATH, or None if there is no such
|
||
|
file.
|
||
|
|
||
|
`mode` defaults to os.F_OK | os.X_OK. `path` defaults to the result
|
||
|
of os.environ.get("PATH"), or can be overridden with a custom search
|
||
|
path.
|
||
|
|
||
|
"""
|
||
|
# Check that a given file can be accessed with the correct mode.
|
||
|
# Additionally check that `file` is not a directory, as on Windows
|
||
|
# directories pass the os.access check.
|
||
|
def _access_check(fn, mode):
|
||
|
return (os.path.exists(fn) and os.access(fn, mode)
|
||
|
and not os.path.isdir(fn))
|
||
|
|
||
|
# If we're given a path with a directory part, look it up directly rather
|
||
|
# than referring to PATH directories. This includes checking relative to the
|
||
|
# current directory, e.g. ./script
|
||
|
if os.path.dirname(cmd):
|
||
|
if _access_check(cmd, mode):
|
||
|
return cmd
|
||
|
return None
|
||
|
|
||
|
if path is None:
|
||
|
path = os.environ.get("PATH", os.defpath)
|
||
|
if not path:
|
||
|
return None
|
||
|
path = path.split(os.pathsep)
|
||
|
|
||
|
if sys.platform == "win32":
|
||
|
# The current directory takes precedence on Windows.
|
||
|
if not os.curdir in path:
|
||
|
path.insert(0, os.curdir)
|
||
|
|
||
|
# PATHEXT is necessary to check on Windows.
|
||
|
pathext = os.environ.get("PATHEXT", "").split(os.pathsep)
|
||
|
# See if the given file matches any of the expected path extensions.
|
||
|
# This will allow us to short circuit when given "python.exe".
|
||
|
# If it does match, only test that one, otherwise we have to try
|
||
|
# others.
|
||
|
if any(cmd.lower().endswith(ext.lower()) for ext in pathext):
|
||
|
files = [cmd]
|
||
|
else:
|
||
|
files = [cmd + ext for ext in pathext]
|
||
|
else:
|
||
|
# On other platforms you don't have things like PATHEXT to tell you
|
||
|
# what file suffixes are executable, so just pass on cmd as-is.
|
||
|
files = [cmd]
|
||
|
|
||
|
seen = set()
|
||
|
for dir in path:
|
||
|
normdir = os.path.normcase(dir)
|
||
|
if not normdir in seen:
|
||
|
seen.add(normdir)
|
||
|
for thefile in files:
|
||
|
name = os.path.join(dir, thefile)
|
||
|
if _access_check(name, mode):
|
||
|
return name
|
||
|
return None
|