| """distutils.spawn | |
| Provides the 'spawn()' function, a front-end to various platform- | |
| specific functions for launching another program in a sub-process. | |
| Also provides the 'find_executable()' to search the path for a given | |
| executable name. | |
| """ | |
| import sys | |
| import os | |
| import os.path | |
| def find_executable(executable, path=None): | |
| """Tries to find 'executable' in the directories listed in 'path'. | |
| A string listing directories separated by 'os.pathsep'; defaults to | |
| os.environ['PATH']. Returns the complete filename or None if not found. | |
| """ | |
| _, ext = os.path.splitext(executable) | |
| if (sys.platform == 'win32') and (ext != '.exe'): | |
| executable = executable + '.exe' | |
| if os.path.isfile(executable): | |
| return executable | |
| if path is None: | |
| path = os.environ.get('PATH', None) | |
| if path is None: | |
| try: | |
| path = os.confstr("CS_PATH") | |
| except (AttributeError, ValueError): | |
| # os.confstr() or CS_PATH is not available | |
| path = os.defpath | |
| # bpo-35755: Don't use os.defpath if the PATH environment variable is | |
| # set to an empty string | |
| # PATH='' doesn't match, whereas PATH=':' looks in the current directory | |
| if not path: | |
| return None | |
| paths = path.split(os.pathsep) | |
| for p in paths: | |
| f = os.path.join(p, executable) | |
| if os.path.isfile(f): | |
| # the file exists, we have a shot at spawn working | |
| return f | |
| return None |