MD5SUM(M)                Debian GNU/Linux               MD5SUM(M)



NAME
       md5sum - generates or checks MD5 message digests


SYNOPSIS
       md5sum [-bv] [-c [file]] | [file...]


DESCRIPTION
       md5sum generates or checks MD5 checksums. The algorithm to
       generate the checksum is reasonably fast and strong enough
       for most cases. Exact specification of the algorithm is in
       RFC 1321.

       Normally md5sum generates checksums of all files given  to
       it as a parameter and prints the checksums followed by the
       filenames. If, however, -c is specified, only one filename
       parameter  is  allowed. This file should contain checksums
       and filenames to which these checksums refer to,  and  the
       files  listed  in that file are checked against the check-
       sums listed there. See option -c for more information.


   OPTIONS
       -b     Use binary mode. In unix environment, only  differ-
              ence between this and the normal mode is an asterix
              preceding the filename in the output.

       -c     Check md5sum of all files listed  in  file  against
              the  checksum  listed  in the same file. The actual
              format of that  file  is  the  same  as  output  of
              md5sum.  That is, each line in the file describes a
              file. A line looks like:

              <MD5 checksum> <filename>

              So, for example, if a file was created and its mes-
              sage digest calculated like so:

              echo foo > md5-test-file; md5sum md5-test-file

              md5sum would report:

              d3b07384d113edec49eaa6238ad5ff00  md5-test-file


       -v     Be  more  verbose.  Print  filenames  when checking
              (with -c).


BUGS
       The related MD4 message digest  algorithm  was  broken  in
       October  1995.  MD5 isn't looking as secure as it used to.

       This manpage is not  quite  accurate  and  has  formatting
       inconsistent with other manpages.

       md5sum does not accept standard options like --help.


AUTHOR
       md5sum  was  originally  written  by Branko Lankester, and
       modified afterwards by Colin Plumb and Ian Jackson (ijack-
       son@gnu.ai.mit.edu).  Manual  page was added by Juho Vuori
       (javuori@cc.helsinki.fi)



Lankester et al         29th November 1995              MD5SUM(M)