cmp(1)								       cmp(1)



NAME
  cmp - Compares two files

SYNOPSIS

  cmp [-l | -s] file1 file2

  The cmp command compares two files.

FLAGS

  -l  Prints the byte number (decimal) and the differing bytes (octal) for
      each difference.

  -s  Does not print data for differing files; returns only an exit value.

DESCRIPTION

  If file1 is - (dash), standard input is used.	 By default, the cmp command
  prints no information if the files are the same.  If the files differ, cmp
  prints the byte and line number where the difference occurred.  The cmp
  command also specifies whether one file is an initial subsequence of the
  other (that is, if the cmp command reads an End-of-File character in one
  file before finding any differences).	 Normally, you use the cmp command to
  compare nontext files and the diff command to compare text files.

  Note that bytes and lines reported by cmp are numbered from 1.

EXAMPLES

   1.  To determine whether two files are identical, enter:
	    cmp prog.o.bak prog.o


       The preceding command compares the files prog.o.bak and prog.o.	If
       the files are identical, a message is not displayed.  If the files
       differ, the location of the first difference is displayed.  For
       instance:
	    prog.o.bak prog.o differ:  byte 5, line 1


       If the message cmp: EOF on prog.o.bak is displayed, then the first
       part of prog.o is identical to prog.o.bak, but there is additional
       data in prog.o.	If the message cmp: EOF on prog.o is displayed, it is
       prog.o.bak that is the same as prog.o but also contains addition data.

   2.  To display each pair of bytes that differ, enter:
	    cmp -l prog.o.bak prog.o


       This compares the files and then displays the byte number (in decimal)
       and the differing bytes (in octal) for each difference.	For example,
       if the fifth byte is octal 101 in prog.o.bak and 141 in prog.o, then
       the cmp command displays:
	    5 101 141
	     .
	     .


EXIT VALUES

  Exit value 0 is returned for identical files, 1 for differing files, and >1
  for an inaccessible file or a missing argument.

RELATED INFORMATION

  Commands:  comm(1), bdiff(1), diff(1), diff3(1).