xref: /freebsd/usr.bin/cmp/cmp.1 (revision 7431dfd4580e850375fe5478d92ec770344db098)
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31.\"     @(#)cmp.1	8.1 (Berkeley) 6/6/93
32.\" $FreeBSD$
33.\"
34.Dd November 18, 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 | s | x
43.Op Fl hz
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 indent
60.It Fl h
61Do not follow symbolic links.
62.It Fl l
63Print the byte number (decimal) and the differing
64byte values (octal) for each difference.
65.It Fl s
66Print nothing for differing files; return exit
67status only.
68.It Fl x
69Like
70.Fl l
71but prints in hexadecimal and using zero as index
72for the first byte in the files.
73.It Fl z
74For regular files compare file sizes first, and fail the comparison if they
75are not equal.
76.El
77.Pp
78The optional arguments
79.Ar skip1
80and
81.Ar skip2
82are the byte offsets from the beginning of
83.Ar file1
84and
85.Ar file2 ,
86respectively, where the comparison will begin.
87The offset is decimal by default, but may be expressed as a hexadecimal
88or octal value by preceding it with a leading ``0x'' or ``0''.
89.Sh EXIT STATUS
90The
91.Nm
92utility exits with one of the following values:
93.Bl -tag -width 4n
94.It 0
95The files are identical.
96.It 1
97The files are different; this includes the case
98where one file is identical to the first part of
99the other.
100In the latter case, if the
101.Fl s
102option has not been specified,
103.Nm
104writes to standard error that EOF was reached in the shorter
105file (before any differences were found).
106.It >1
107An error occurred.
108.El
109.Sh SEE ALSO
110.Xr diff 1 ,
111.Xr diff3 1
112.Sh STANDARDS
113The
114.Nm
115utility is expected to be
116.St -p1003.2
117compatible.
118The
119.Fl h ,
120.Fl x ,
121and
122.Fl z
123options are extensions to the standard.
124.Sh HISTORY
125A
126.Nm
127command appeared in
128.At v1 .
129