开关用错了,看下面红色文字
MD5  --  Calculate MD5 signature of file.  Call
         with md5  
         Options:
              -csig   Check against sig, set exit status 0 = OK
             
 -dtext  Compute signature of text argument
              -l      Use lower case letters for hexadecimal digits
              -n      Do not show file name after sum
              -ofname Write output to fname (- = stdout)
              -u      Print this message
              -v      Print version information
by John Walker  --  
http://www.fourmilab.ch/
Version 2.2 (2008-01-14)
This program is in the public domain.