1: #!/usr/bin/rexx
   2: 
   3: parse arg ifn   -- get input filename
   4: input_stream = .stream~new(ifn)
   5: message_digest = .md5~new
   6: do while input_stream~chars>0
   7:   -- calculate digest in chunks of 256 bytes
   8:   message_digest~update(input_stream~charin(,256))
   9: end
  10: say message_digest~digest
  11: exit
  12: 
  13: ::requires "md5.cls"