windows.py 文件源码

def _wmic_output():
    """
    Returns the output from running the built-in `wmic` command.

    Redirects the output of `wmic` to a temporary file and then reads it back in.
    This would be cleaner if done using subprocess, but attempting to capture
    `stdout` internally led to freezing under Windows XP. (This may have been
    happening because the script is not being run as a main process.)
    """

    # choose a unique file name (re-entrant/thread-safe/crash-safe)
    OUTPUT_PATH = os.path.join(
        tempfile.gettempdir(),
        "kolibri_disks-{}.txt".format(uuid.uuid4())
    )

    # pipe output from the WMIC command to the temp file
    cmd = "wmic logicaldisk list full /format:csv > {}".format(OUTPUT_PATH)
    returnCode = os.system(cmd)
    if returnCode:
        raise Exception("Could not run command '{}'".format(cmd))

    # output from WMIC is ostensibly UTF-16
    with open(OUTPUT_PATH, 'rb') as f:
        bin_output = f.read()

    # The very first time WMIC is run on a windows machine, the output gets mangled.
    # The BOM is replaced by WMIC's initialization message, so we need to put it back.
    # (On all subsequent runs, these next lines do nothing.)
    INIT_MSG = "Please wait while WMIC is being installed.".encode('ascii')  # Yes, ascii.
    bin_output = bin_output.replace(INIT_MSG, codecs.BOM_UTF16)

    # finally, decode the well-formatted UTF-16 byte string
    output = bin_output.decode('utf-16')

    # clean up temp file
    os.remove(OUTPUT_PATH)

    return output