DragonFly On-Line Manual Pages

CMP(1)                 DragonFly General Commands Manual                CMP(1)

NAME
     cmp - compare two files

SYNOPSIS
     cmp [-l, --verbose | -s, --silent, --quiet | -x] [-hz] file1 file2
         [skip1 [skip2]]

DESCRIPTION
     The cmp utility compares two files of any type and writes the results to
     the standard output.  By default, cmp is silent if the files are the
     same; if they differ, the byte and line number at which the first
     difference occurred is reported.

     Bytes and lines are numbered beginning with one.

     The following options are available:

     -h      Do not follow symbolic links.

     -l, --verbose
             Print the byte number (decimal) and the differing byte values
             (octal) for each difference.

     -s, --silent, --quiet
             Print nothing for differing files; return exit status only.

     -x      Like -l but prints in hexadecimal and using zero as index for the
             first byte in the files.

     -z      For regular files compare file sizes first, and fail the
             comparison if they are not equal.

     The optional arguments skip1 and skip2 are the byte offsets from the
     beginning of file1 and file2, respectively, where the comparison will
     begin.  The offset is decimal by default, but may be expressed as a
     hexadecimal or octal value by preceding it with a leading ``0x'' or
     ``0''.

EXIT STATUS
     The cmp utility exits with one of the following values:

     0     The files are identical.

     1     The files are different; this includes the case where one file is
           identical to the first part of the other.  In the latter case, if
           the -s option has not been specified, cmp writes to standard error
           that EOF was reached in the shorter file (before any differences
           were found).

     >1    An error occurred.

EXAMPLES
     Assuming a file named example.txt with the following contents:

           a
           b
           c

     Compare stdin with example.txt:

           $ echo -e "a\nb\nc" | cmp - example.txt

     Same as above but introducing a change in the third byte of stdin.  Show
     the byte number (decimal) and differing byte (octal):

           $ echo -e "a\nR\nc" | cmp -l - example.txt
                3 122 142

     Compare file sizes of example.txt and /boot/loader.conf and return 1 if
     they are not equal.  Note that -z can only be used with regular files:

           $ cmp -z example.txt /boot/loader.conf
           example.txt /boot/loader.conf differ: size

     Compare stdin with example.txt omitting the first 4 bytes from stdin and
     the first 2 bytes from example.txt:

           $ echo -e "a\nR\nb\nc" | cmp - example.txt 4 2

SEE ALSO
     diff(1), diff3(1)

STANDARDS
     The cmp utility is expected to be IEEE Std 1003.2 ("POSIX.2") compatible.
     The -h, -x, and -z options are extensions to the standard.

HISTORY
     A cmp command appeared in Version 1 AT&T UNIX.

DragonFly 5.9-DEVELOPMENT      January 15, 2021      DragonFly 5.9-DEVELOPMENT