.Dd August 13, 1999
.Dt MD5 1
.Os NetBSD 1.4
.Sh NAME
.Nm md5
.Nd checksumming utility
.Sh SYNOPSIS
.Nm md5
.Op Fl flags ...
.Op Ar file ...
.Sh DESCRIPTION
.Nm md5
computes MD5 checksums (see RFC-1321).
.Pp
If no
.Ar file Ns names
are given,
.Nm
checksums its standard input; otherwise, it checksums the named files.
Each checksum is printed on a separate line.  By default, if multiple
files were given, each checksum is followed by the name of the file it
corresponds to; if only one file was given, or if stdin is being
checksummed, the checksum is printed by itself.
.Pp
Flags currently understood are:
.Bl -tag -width indent
.It Fl h
Never print names with the checksums, even when multiple filenames are
given.
.It Fl H
Always print names with the checksums, even when only one filename, or
none, is given.  (The
.Sq name
printed when standard input is checksummed is
.Dq stdin . )
.It Fl c
Compatability mode output: print checksums in the
.Bd -literal -offset indent
MD5 (foo) = 0123456789abcdef0123456789abcdef
.Ed
format used by some other MD5 checksumming programs.  With this option,
.Fl h
and
.Fl H
are ignored, and the name is always printed when checksumming a file
and never when checksumming stdin (checksums of stdin are printed with
no commentary at all).
.El
.Pp
Exit status is a count of the number of files that couldn't be opened
(normally zero).  Such files produce a complaint on stderr instead of a
checksum line on stdout.
.Sh EXAMPLES
.Bd -literal -offset indent
% echo foo | md5
d3b07384d113edec49eaa6238ad5ff00
% cat file1
This is file #1.
% cat file2
This is (slightly longer) file #2.
It has two lines.
% md5 file1 file2
d807e60c4201139dffe2614cb5580ab7 file1
68a115f3b08ffea71ad051a351e3fc35 file2
% 
.Ed
.Sh AUTHOR
der Mouse,
.Aq mouse@rodents.montreal.qc.ca .