我知道我在这里有点像死灵法师，但我偶然发现了这个问题，并且接受的解决方案不适用于所有情况我认为无论如何提交可能很有用。特别是“可执行”模式检测，以及提供文件扩展名的要求。此外，python3.3 的shutil.which（使用PATHEXT）和python2.4+ 的distutils.spawn.find_executable（只是尝试添加'.exe'）都只适用于部分情况。
所以我写了一个“超级”版本（基于接受的答案，以及来自 Suraj 的 PATHEXT 建议）。这个版本的which 更彻底地完成了任务，首先尝试了一系列“broadphase”广度优先技术，最终在PATH 空间上尝试更细粒度的搜索：
import os
import sys
import stat
import tempfile
def is_case_sensitive_filesystem():
tmphandle, tmppath = tempfile.mkstemp()
is_insensitive = os.path.exists(tmppath.upper())
os.close(tmphandle)
os.remove(tmppath)
return not is_insensitive
_IS_CASE_SENSITIVE_FILESYSTEM = is_case_sensitive_filesystem()
def which(program, case_sensitive=_IS_CASE_SENSITIVE_FILESYSTEM):
""" Simulates unix `which` command. Returns absolute path if program found """
def is_exe(fpath):
""" Return true if fpath is a file we have access to that is executable """
accessmode = os.F_OK | os.X_OK
if os.path.exists(fpath) and os.access(fpath, accessmode) and not os.path.isdir(fpath):
filemode = os.stat(fpath).st_mode
ret = bool(filemode & stat.S_IXUSR or filemode & stat.S_IXGRP or filemode & stat.S_IXOTH)
return ret
def list_file_exts(directory, search_filename=None, ignore_case=True):
""" Return list of (filename, extension) tuples which match the search_filename"""
if ignore_case:
search_filename = search_filename.lower()
for root, dirs, files in os.walk(path):
for f in files:
filename, extension = os.path.splitext(f)
if ignore_case:
filename = filename.lower()
if not search_filename or filename == search_filename:
yield (filename, extension)
break
fpath, fname = os.path.split(program)
# is a path: try direct program path
if fpath:
if is_exe(program):
return program
elif "win" in sys.platform:
# isnt a path: try fname in current directory on windows
if is_exe(fname):
return program
paths = [path.strip('"') for path in os.environ.get("PATH", "").split(os.pathsep)]
exe_exts = [ext for ext in os.environ.get("PATHEXT", "").split(os.pathsep)]
if not case_sensitive:
exe_exts = map(str.lower, exe_exts)
# try append program path per directory
for path in paths:
exe_file = os.path.join(path, program)
if is_exe(exe_file):
return exe_file
# try with known executable extensions per program path per directory
for path in paths:
filepath = os.path.join(path, program)
for extension in exe_exts:
exe_file = filepath+extension
if is_exe(exe_file):
return exe_file
# try search program name with "soft" extension search
if len(os.path.splitext(fname)[1]) == 0:
for path in paths:
file_exts = list_file_exts(path, fname, not case_sensitive)
for file_ext in file_exts:
filename = "".join(file_ext)
exe_file = os.path.join(path, filename)
if is_exe(exe_file):
return exe_file
return None
用法如下：
>>> which.which("meld")
'C:\\Program Files (x86)\\Meld\\meld\\meld.exe'
在这种情况下，接受的解决方案对我不起作用，因为目录中还有 meld.1、meld.ico、meld.doap 等文件，其中一个被返回（大概是从字典顺序开始）因为已接受答案中的可执行测试不完整并给出误报。