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Diffstat (limited to 'usr.bin/cmp/cmp.1')
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diff --git a/usr.bin/cmp/cmp.1 b/usr.bin/cmp/cmp.1 new file mode 100644 index 000000000000..ab797fa89e2a --- /dev/null +++ b/usr.bin/cmp/cmp.1 @@ -0,0 +1,210 @@ +.\" Copyright (c) 1987, 1990, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" This code is derived from software contributed to Berkeley by +.\" the Institute of Electrical and Electronics Engineers, Inc. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.Dd September 23, 2021 +.Dt CMP 1 +.Os +.Sh NAME +.Nm cmp +.Nd compare two files +.Sh SYNOPSIS +.Nm +.Op Fl l | s | x +.Op Fl bhz +.Op Fl -ignore-initial Ns Cm = Ns Ar num1 Ns Op :num2 +.Op Fl -bytes Ns Cm = Ns Ar num +.Ar file1 file2 +.Op Ar skip1 Op Ar skip2 +.Sh DESCRIPTION +The +.Nm +utility compares two files of any type and writes the results +to the standard output. +By default, +.Nm +is silent if the files are the same; if they differ, the byte +and line number at which the first difference occurred is reported. +.Pp +Bytes and lines are numbered beginning with one. +.Pp +The following options are available: +.Bl -tag -width indent +.It Fl b , Fl -print-bytes +Print each byte when a difference is found. +.It Fl h +Do not follow symbolic links. +.It Fl i Ar num1 Ns Oo :num2 Oc , Fl -ignore-initial= Ns Ar num1 Ns Op :num2 +Skip +.Ar num1 +bytes from +.Ar file1 , +and optionally skip +.Ar num2 +bytes from +.Ar file2 . +If +.Ar num2 +is not specified, then +.Ar num1 +is applied for both +.Ar file1 +and +.Ar file2 . +.It Fl l , Fl -verbose +Print the byte number (decimal) and the differing +byte values (octal) for each difference. +.It Fl n Ar num , Fl -bytes= Ns num +Only compare up to +.Ar num +bytes. +.It Fl s , Fl -silent , Fl -quiet +Print nothing for differing files; return exit +status only. +.It Fl x +Like +.Fl l +but prints in hexadecimal and using zero as index +for the first byte in the files. +.It Fl z +For regular files compare file sizes first, and fail the comparison if they +are not equal. +.El +.Pp +The optional arguments +.Ar skip1 +and +.Ar skip2 +are the byte offsets from the beginning of +.Ar file1 +and +.Ar file2 , +respectively, where the comparison will begin. +The offset is decimal by default, but may be expressed as a hexadecimal +or octal value by preceding it with a leading ``0x'' or ``0''. +.Pp +.Ar skip1 +and +.Ar skip2 +may also be specified with SI size suffixes. +.Sh EXIT STATUS +The +.Nm +utility exits with one of the following values: +.Bl -tag -width 4n +.It 0 +The files are identical. +.It 1 +The files are different; this includes the case +where one file is identical to the first part of +the other. +In the latter case, if the +.Fl s +option has not been specified, +.Nm +writes to standard error that EOF was reached in the shorter +file (before any differences were found). +.It >1 +An error occurred. +.El +.Sh EXAMPLES +Assuming a file named +.Pa example.txt +with the following contents: +.Bd -literal -offset indent +a +b +c +.Ed +.Pp +Compare stdin with +.Pa example.txt : +.Bd -literal -offset indent +$ echo -e "a\\nb\\nc" | cmp - example.txt +.Ed +.Pp +Same as above but introducing a change in the third byte of stdin. +Show the byte number (decimal) and differing byte (octal): +.Bd -literal -offset indent +$ echo -e "a\\nR\\nc" | cmp -l - example.txt + 3 122 142 +.Ed +.Pp +Compare file sizes of +.Pa example.txt +and +.Pa /boot/loader.conf +and return 1 if they are not equal. +Note that +.Fl z +can only be used with regular files: +.Bd -literal -offset indent +$ cmp -z example.txt /boot/loader.conf +example.txt /boot/loader.conf differ: size +.Ed +.Pp +Compare stdin with +.Pa example.txt +omitting the first 4 bytes from stdin and the first 2 bytes from +.Pa example.txt : +.Bd -literal -offset indent +$ echo -e "a\\nR\\nb\\nc" | cmp - example.txt 4 2 +.Ed +.Sh SEE ALSO +.Xr diff 1 , +.Xr diff3 1 +.Sh STANDARDS +The +.Nm +utility is expected to be +.St -p1003.2 +compatible. +The +.Fl b , +.Fl h , +.Fl i , +.Fl n , +.Fl x , +and +.Fl z +options are extensions to the standard. +.Ar skip1 +and +.Ar skip2 +arguments are extensions to the standard. +.Sh HISTORY +A +.Nm +command appeared in +.At v1 . +.Sh BUGS +The phrase +.Dq SI size suffixes +above refers to the traditional power of two convention, as described in +.Xr expand_number 3 . |