Ubuntu Manpages

md5sum

compute and check MD5 message digest

md5sum [OPTION]... [FILE]...

Print or check MD5 (128-bit) checksums. With no FILE, or when FILE is -, read standard input.

read in binary mode
read MD5 sums from the FILEs and check them
create a BSD-style checksum
read in text mode (default)

don't print OK for each successfully verified file
don't output anything, status code shows success
warn about improperly formatted checksum lines
with --check, exit non-zero for any invalid input
display this help and exit
output version information and exit

The sums are computed as described in RFC 1321. When checking, the input should be a former output of this program. The default mode is to print a line with checksum, a character indicating input mode ('*' for binary, space for text), and name for each FILE.

The MD5 algorithm should not be used any more for security related purposes. Instead, better use an SHA-2 algorithm, implemented in the programs sha224sum(1), sha256sum(1), sha384sum(1), sha512sum(1)

Written by Ulrich Drepper, Scott Miller, and David Madore.

Report md5sum bugs to bug-coreutils@gnu.org
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
Report md5sum translation bugs to <http://translationproject.org/team/>

Copyright © 2013 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

The full documentation for md5sum is maintained as a Texinfo manual. If the info and md5sum programs are properly installed at your site, the command

info coreutils 'md5sum invocation'

should give you access to the complete manual.