xref: /dragonfly/usr.bin/cmp/cmp.1 (revision e65bc1c3)
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31.\"     @(#)cmp.1	8.1 (Berkeley) 6/6/93
32.\" $FreeBSD: src/usr.bin/cmp/cmp.1,v 1.7.2.5 2003/02/24 22:37:41 trhodes Exp $
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34.Dd April 10, 2013
35.Dt CMP 1
36.Os
37.Sh NAME
38.Nm cmp
39.Nd compare two files
40.Sh SYNOPSIS
41.Nm
42.Op Fl l | Fl s | Fl x
43.Op Fl z
44.Ar file1 file2
45.Op Ar skip1 Op Ar skip2
46.Sh DESCRIPTION
47The
48.Nm
49utility compares two files of any type and writes the results
50to the standard output.
51By default,
52.Nm
53is silent if the files are the same; if they differ, the byte
54and line number at which the first difference occurred is reported.
55.Pp
56Bytes and lines are numbered beginning with one.
57.Pp
58The following options are available:
59.Bl -tag -width flag
60.It Fl l
61Print the byte number (decimal) and the differing
62byte values (octal) for each difference.
63.It Fl s
64Print nothing for differing files; return exit
65status only.
66.It Fl x
67Like
68.Fl l
69but prints in hexadecimal and using zero as index
70for the first byte in the files.
71.It Fl z
72For regular files compare file sizes first, and fail the comparison if they
73are not equal.
74.El
75.Pp
76The optional arguments
77.Ar skip1
78and
79.Ar skip2
80are the byte offsets from the beginning of
81.Ar file1
82and
83.Ar file2 ,
84respectively, where the comparison will begin.
85The offset is decimal by default, but may be expressed as a hexadecimal
86or octal value by preceding it with a leading ``0x'' or ``0''.
87.Sh EXIT STATUS
88The
89.Nm
90utility exits with one of the following values:
91.Bl -tag -width 4n
92.It 0
93The files are identical.
94.It 1
95The files are different; this includes the case
96where one file is identical to the first part of
97the other.
98In the latter case, if the
99.Fl s
100option has not been specified,
101.Nm
102writes to standard error that EOF was reached in the shorter
103file (before any differences were found).
104.It >1
105An error occurred.
106.El
107.Sh COMPATIBILITY
108The
109.Fl x
110and
111.Fl z
112options are extensions to the standard.
113.Sh SEE ALSO
114.Xr diff 1 ,
115.Xr diff3 1
116.Sh STANDARDS
117The
118.Nm
119utility is expected to be
120.St -p1003.2
121compatible.
122.Sh HISTORY
123A
124.Nm
125command appeared in
126.At v1 .
127