xref: /original-bsd/usr.bin/cmp/cmp.1 (revision b7261a4b)
1.\" Copyright (c) 1987, 1990 The Regents of the University of California.
2.\" All rights reserved.
3.\"
4.\" %sccs.include.redist.man%
5.\"
6.\"     @(#)cmp.1	6.3 (Berkeley) 06/11/90
7.\"
8.Dd
9.Dt CMP 1
10.Os BSD 4.4
11.Sh NAME
12.Nm cmp
13.Nd compare two files
14.Sh SYNOPSIS
15.Nm cmp
16.Op Fl l Fl s
17.Ar file1 file2
18.Sh DESCRIPTION
19The cmp utility compares two files.
20Under default options,
21cmp writes no output if the files are the same; if they
22differ, it writes to standard output the byte and line
23number at which the first difference occurred.
24Bytes and
25lines are numbered beginning with one.
26.Pp
27The following options are available:
28.Tp Fl l
29Print the byte number (decimal) and the differing
30bytes (octal) for each difference.
31.Tp Fl s
32Print nothing for differing files; return exit
33status only.
34.Tp
35.Pp
36Nothing is guaranteed if both
37.Fl s
38and
39.Fl l
40are given.
41.Pp
42The following operands are available:
43.Tw file1
44.Tp Ar file1
45A pathname of the first file to be compared.
46If
47.Ar file1
48is
49.Cx Fl
50.Cx ,
51.Cx
52the standard input is used.
53.Tp Ar file2
54A pathname of the second file to be compared.
55.Tp
56.Pp
57The input files can be any file type.
58.Pp
59Results of the comparison are written to standard output.
60When no options are used, the format is:
61.Pp
62.Ds I
63"%s %s differ: char %d, line %d\en", <file1>,
64<file2>, <byte number>, <line number>
65.De
66.Pp
67When the
68.Fl l
69option is used, the format is:
70.Pp
71.Ds I
72"%d %o %o\en", <byte number>, <differing byte>,
73<differing byte>
74.De
75.Pp
76for each byte that differs.  The first byte number is from
77file1 while the second is from file2.
78.Pp
79If file1 and file2 are identical for the entire length of
80the shorter file, the following format is used, unless the
81.Fl s
82option is specified.
83.Pp
84.Ds I
85"cmp: EOF on %s\en", <name of shorter file>
86.De
87.Pp
88No output is written to standard output when the
89.Fl s option
90is used.
91.Pp
92The
93.Nm cmp
94utility exits with one of the following values:
95.Tw Fl
96.Tp 0
97The files are identical.
98.Tp 1
99The files are different; this includes the case
100where one file is identical to the first part of
101the other.
102In the latter case, if the -s option has
103not been specified, cmp writes to standard error
104that EOF was reached in the shorter file (before
105any differences were found).
106.Tp >1
107An error occurred.
108.Tp
109.Sh SEE ALSO
110diff 1 ,
111diff3 1
112.Sh STANDARDS
113The
114.Nm cmp
115function is expected to be POSIX 1003.2 compatible.
116