xref: /dragonfly/usr.bin/cmp/cmp.1 (revision 89a89091)
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35.\"     @(#)cmp.1	8.1 (Berkeley) 6/6/93
36.\" $FreeBSD: src/usr.bin/cmp/cmp.1,v 1.7.2.5 2003/02/24 22:37:41 trhodes Exp $
37.\" $DragonFly: src/usr.bin/cmp/cmp.1,v 1.2 2003/06/17 04:29:25 dillon Exp $
38.\"
39.Dd July 23, 2009
40.Dt CMP 1
41.Os
42.Sh NAME
43.Nm cmp
44.Nd compare two files
45.Sh SYNOPSIS
46.Nm
47.Op Fl l | Fl s | Fl x
48.Op Fl z
49.Ar file1 file2
50.Op Ar skip1 Op Ar skip2
51.Sh DESCRIPTION
52The
53.Nm
54utility compares two files of any type and writes the results
55to the standard output.
56By default,
57.Nm
58is silent if the files are the same; if they differ, the byte
59and line number at which the first difference occurred is reported.
60.Pp
61Bytes and lines are numbered beginning with one.
62.Pp
63The following options are available:
64.Bl -tag -width flag
65.It Fl l
66Print the byte number (decimal) and the differing
67byte values (octal) for each difference.
68.It Fl s
69Print nothing for differing files; return exit
70status only.
71.It Fl x
72Like
73.Fl l
74but prints in hexadecimal and using zero as index
75for the first byte in the files.
76.It Fl z
77For regular files compare file sizes first, and fail the comparison if they
78are not equal.
79.El
80.Pp
81The optional arguments
82.Ar skip1
83and
84.Ar skip2
85are the byte offsets from the beginning of
86.Ar file1
87and
88.Ar file2 ,
89respectively, where the comparison will begin.
90The offset is decimal by default, but may be expressed as a hexadecimal
91or octal value by preceding it with a leading ``0x'' or ``0''.
92.Pp
93The
94.Nm
95utility exits with one of the following values:
96.Bl -tag -width 4n
97.It 0
98The files are identical.
99.It 1
100The files are different; this includes the case
101where one file is identical to the first part of
102the other.
103In the latter case, if the
104.Fl s
105option has not been specified,
106.Nm
107writes to standard error that EOF was reached in the shorter
108file (before any differences were found).
109.It >1
110An error occurred.
111.El
112.Sh COMPATIBILITY
113The
114.Fl x
115and
116.Fl z
117options are extensions to the standard.
118.Sh SEE ALSO
119.Xr diff 1 ,
120.Xr diff3 1
121.Sh STANDARDS
122The
123.Nm
124utility is expected to be
125.St -p1003.2
126compatible.
127.Sh HISTORY
128A
129.Nm
130command appeared in
131.At v1 .
132