CMP(P)                                                     CMP(P)



NAME
       cmp (GNU diffutils) - compare two files or byte ranges

SYNOPSIS
       cmp  [-clsv]  [-i NUM] [--help] [--print-chars] [--ignore-
       initial=NUM] [--verbose] [--quiet] [--silent]  [--version]
       -I FILE1 [FILE2 [RANGE1 [RANGE2]]]

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.

       In the output, bytes and lines are numbered beginning with
       one; however, range inputs are zero-based; see  below  for
       details.  A filename of - represents standard input.

       The following options are available:
       -c, --print-chars
              Output  the  differing  bytes as characters, rather
              than as octal  numbers.   Non-printable  characters
              will be shown in  form.
       -i NUM, --ignore-initial=NUM
              Ignore NUM initial characters from each file.  This
              is a synonym for specifying  NUM  NUM  as  the  two
              RANGE arguments.
       -l, --verbose
              Print  the  byte number (decimal) and the differing
              byte values (octal) for each difference.
       -s, --quiet, --silent
              Print nothing for differing files; return exit sta-
              tus only.
       -v, --version
              Print the diffutils version number.

BYTE RANGES
       The  two  optional  arguments  RANGE1 and RANGE2 represent
       byte ranges to compare within the files.  Each  range  can
       be expressed in several ways:
       M+N    Skip  M  bytes  at the beginning of the input, then
              compare a maximum of N bytes.
       M-N, M,N
              Skip M bytes at the beginning  of  the  input,  and
              read  between  bytes  M and N, which are both zero-
              based.

       In either case, both M and N are optional and  default  to
       beginning  and  end  of  file, respectively.  In addition,
       they can be expressed in decimal, octal (0NNN) or hexadec-
       imal (0xNNN) form.

NOTES
       The  zero-based  range  numbers may seem inconsistent with
       cmp output, which is one-based; this is for  compatibility
       with  some  versions  of  cmp  which  allow "skip N bytes"
       parameters after the filenames; in this context, the N  is
       zero-based.

DIAGNOSTICS
       The cmp utility exits with one of the following values:
       0      The files or byte ranges are identical.
       1      The  files  or  byte  ranges  are  different;  this
              includes the case where one file or range is  iden-
              tical  to the first part of the other.  In the lat-
              ter case, if -s has not been specified, cmp  writes
              to  standard  output  that  EOF  was reached in the
              shorter file.
       >1     An error occurred.

SEE ALSO
       diff(f), diff3(3)

STANDARDS
       The cmp utility is expected to be POSIX  1003.2-compliant.



GNU Project             1998 September 23                  CMP(P)