md5sum – compute and check MD5 message digest



Computes the signature of the specified infile or the string supplied by the -d option and compares it against the specified signature. If the two signatures match, the exit status will be zero, otherwise the exit status will be 1. No signature is written; only the exit status is set. The signature to be checked must be specified as 32 hexadecimal digits.
A signature is computed for the given input_text (which must be quoted if it contains white space characters) instead of input from infile or standard input. If input is specified with the -d option, no infile should be specified.
Use lower case letters for hexadecimal digits “a” through “f”. By default, upper case letters are used. Note that the signature argument to the -c option may use upper or lower case hexadecimal digits (or a mix) regardless of the setting of this option.
Suppress printing the file name (or “-” for standard input) after the hexadecimal signature.
Write output to fname. If fname is “-”, output is written to standard output, which is the default is no -o option is specified.
Print how-to-call information.
Print version information.