md5sum -- generate or check MD5 message digests


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


For each file, write to standard output a line containing the MD5 message digest of that file, followed by one or more blank characters, followed by the name of the file. The MD5 message digest shall be calculated according to RFC 1321: The MD5 Message-Digest Algorithm and output as 32 hexadecimal digits.

If no file names are specified as operands, read from standard input and use "-" as the file name in the output.


-c [file] 

checks the MD5 message digest of all files named in file against the message digest listed in the same file. The actual format of file is the same as the output of md5sum. That is, each line in the file describes a file. If file is not specified, read message digests from stdin.

Exit Status

md5sum shall exit with status 0 if the sum was generated successfully, or, in check mode, if the check matched. Otherwise, md5sum shall exit with a non-zero status.