xref: /openbsd/usr.bin/cmp/cmp.1 (revision 404b540a)
1.\"     $OpenBSD: cmp.1,v 1.14 2009/02/08 17:15:09 jmc Exp $
2.\"     $NetBSD: cmp.1,v 1.4 1995/09/08 03:22:55 tls Exp $
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34.\"     @(#)cmp.1	8.1 (Berkeley) 6/6/93
35.\"
36.Dd $Mdocdate: February 8 2009 $
37.Dt CMP 1
38.Os
39.Sh NAME
40.Nm cmp
41.Nd compare two files
42.Sh SYNOPSIS
43.Nm cmp
44.Op Fl l | Fl s
45.Ar file1 file2
46.Op Ar skip1 Op Ar skip2
47.Sh DESCRIPTION
48The
49.Nm
50utility compares two files of any type and writes the results
51to the standard output.
52By default,
53.Nm
54is silent if the files are the same; if they differ, the byte
55and line number at which the first difference occurred is reported.
56.Pp
57Bytes and lines are numbered beginning with one.
58.Pp
59The options are as follows:
60.Bl -tag -width Ds
61.It Fl l
62Print the byte number (decimal) and the differing
63byte values (octal) for each difference.
64.It Fl s
65Print nothing for differing files; return exit
66status only.
67.El
68.Pp
69The optional arguments
70.Ar skip1
71and
72.Ar skip2
73are the byte offsets from the beginning of
74.Ar file1
75and
76.Ar file2 ,
77respectively, where the comparison will begin.
78The offset is decimal by default, but may be expressed as a hexadecimal
79or octal value by preceding it with a leading
80.Dq 0x
81or
82.Dq 0 .
83.Pp
84The
85.Nm
86utility exits with one of the following values:
87.Bl -tag -width 4n
88.It 0
89The files are identical.
90.It 1
91The files are different; this includes the case
92where one file is identical to the first part of
93the other.
94In the latter case, if the
95.Fl s
96option has not been specified,
97.Nm
98writes to standard error that
99.Dv EOF
100was reached in the shorter
101file (before any differences were found).
102.It >1
103An error occurred.
104.El
105.Sh SEE ALSO
106.Xr diff 1 ,
107.Xr diff3 1 ,
108.Xr sdiff 1
109.Sh STANDARDS
110The
111.Nm
112utility is compliant with the
113.St -p1003.1-2008
114specification.
115.Pp
116The arguments
117.Ar skip1
118and
119.Ar skip2
120are extensions to that specification.
121.Sh HISTORY
122A
123.Nm
124command appeared in
125.At v1 .
126