Contents|Index|Previous|Next Invoking cmp The cmp command compares two files, and if they differ, tells the first byte and line number where they differ. Its arguments are: cmp options ... from-file [ to-file]. The file name '-' is always the standard input. cmp also uses the standard input if one file name is omitted. An exit status of 0 means no differences were found, 1 means some differences were found, and 2 means trouble. See also Options to cmp.