platform.py 文件源码

def _syscmd_file(target,default=''):

    """ Interface to the system's file command.

        The function uses the -b option of the file command to have it
        ommit the filename in its output and if possible the -L option
        to have the command follow symlinks. It returns default in
        case the command should fail.

    """
    if sys.platform in ('dos','win32','win16','os2'):
        # XXX Others too ?
        return default
    target = _follow_symlinks(target).replace('"', '\\"')
    try:
        f = os.popen('file "%s" 2> %s' % (target, DEV_NULL))
    except (AttributeError,os.error):
        return default
    output = string.strip(f.read())
    rc = f.close()
    if not output or rc:
        return default
    else:
        return output

### Information about the used architecture

# Default values for architecture; non-empty strings override the
# defaults given as parameters