使用 IF EXIST 或 IF NOT EXIST 组合:

:FindDrive
if exist Z:\nul goto Mounted
timeout /T 5
goto FindDrive
:Mounted

NUL是每个文件夹中都存在的虚拟"文件.因此，如果c:\ anypath \ nul存在，则驱动器存在.

NUL is the a 'virtual' file that exists in every folder. So if c:\anypath\nul exists, the drive exists.