misc-utils/md5sum.1

.\" md5sum.1 -- 
.\" Public Domain 1995 Rik Faith (faith@cs.unc.edu)
.\" Revised: Sat Feb 11 12:16:48 1995 by faith@cs.unc.edu
.\" "
.TH MD5SUM 1 "11 February 1995" "Linux 1.0" "Linux Programmer's Manual"
.SH NAME
md5sum \- generate/check MD5 message digests
.SH SYNOPSIS
.BR "md5sum [" \-bv "] [" \-c
.BR "[ " file " ] ]"
.br
.BR "md5sum " file " ..."
.SH DESCRIPTION
.B md5sum
generates and checks MD5 message digests, as described in RFC-1321.  The
"message digest" produced can be thought of as a 128-bit "signature" of the
input file.  Typically,
.B md5sum
is used to verify the integrity of files made available for distribution
via anonymous ftp (for example, announcements for new versions of
.BR irc(1)
usually contain MD5 signatures).
.P
Message digests for a tree of files can be generated with a command similar
to the following:
.RS
.sp
find . -type f -print | xargs md5sum
.sp
.RE
The output of this command is suitable as input for the
.B \-c
option.
.SH OPTIONS
.TP
.BI "\-c [" file "]"
Check message digests.  Input is taken from
.B stdin
or from the spcified
.IR file .
The input should be in the same format as the output generated by
.BR md5sum .
.TP
.B \-v
Verbose.  Print file names when checking.
.TP
.B \-b
Read files in binary mode (otherwise, end-of-file conventions will be
ignored).
.SH HISTOY
The
.B md5sum
program was written by Branko Lankester and may be freely distributed.  The
original source code is in the MIT PGP 2.6.2 distribution.  Those concerned
about the integrity of this version should obtain the original sources and
compile their own version.
.PP
The underlying implementation of Ron Rivest's MD5 algorithm was written by
Colin Plumb and is in the Public Domain.  (Equivalent code is also
available from RSA Data Security, Inc.)
.SH "SEE ALSO"
.BR sum (1),
.BR cksum (1),
.BR pgp (1)