MD5SUM(1)

NAME
md5sum - compute/verify md5 checksums

SYNOPSIS
md5sum [-bchtvV] [path] [file [...]]
md5sum [--binary, --check, --help, --text, --verbose, --version ] [file [...]]

DESCRIPTION
Md5sum computes or verifies md5 message digests. This message digest can be used as a checksum for a file, and is typically used to verify the autheticity of files made available for distribution via anonymous ftp or the web. Md5sum generates output that can be fed to md5sum -c for verification purposes.

When verifying md5 message digests, md5sum returns a zero status if all files match their message digests, and nonzero if any of them don't.

OPTIONS

-b, --binary
Make message digests for binary files.  Various personal computer operating
    systems use multi-character sequences for end-of-line, and to keep them from collapsing those sequences into \n, --binary needs to be specified. On unix, this option is ignored.

-c, --check
Verify
    md5 digests. Whe md5sum is verifying digests, it reads them off the standard input, in the format digest filename . This, happily, is the format produced by md5sum when it is generating message digests, so the output of md5sum can be used to generate a signature that can be checked elsewhere.

-t, --text
This is the opposite of
    --binary ; on PC operating systems, it collapses end of lines down to \n. On Unix, of course, it is ignored.

-v, --verbose
When verifying md5 message digests, give a line-by-line report of
    what's going on.

-h, --help
Print a help message, then quit.

-v, --version
Print the
    md5sum release version, then quit.

EXAMPLES
To build a md5 message digest listing of all the files in /usr/bin:
    find /usr/bin -type f -print | xargs md5sum > /tmp/digest
To check the contents of /usr/bin against the listing you made in the previous example:
    md5sum --check < /tmp/digest

AUTHOR
David Parsons ( orc@pell.chi.il.us )