'\" te
.\" Copyright 1989 AT&T 
.\" Copyright (c) 2006, 2011, Oracle and/or its affiliates. All rights reserved.
.\" Portions Copyright (c) 1992, X/Open Company Limited All Rights Reserved
.\" Portions Copyright (c) 1982-2007 AT&T Knowledge Ventures
.\" Sun Microsystems, Inc. gratefully acknowledges The Open Group for permission to reproduce portions of its copyrighted documentation. Original documentation from The Open Group can be obtained online at http://www.opengroup.org/bookstore/.
.\" The Institute of Electrical and Electronics Engineers and The Open Group, have given us permission to reprint portions of their documentation. In the following statement, the phrase "this text" refers to portions of the system documentation. Portions of this text are reprinted and reproduced in electronic form in the Sun OS Reference Manual, from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between these versions and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html.  This notice shall appear on any product containing this material.
.TH cmp 1 "25 Jul 2011" "SunOS 5.11" "User Commands"
.SH NAME
cmp \- compare two files
.SH SYNOPSIS
.LP
.nf
\fB/usr/bin/cmp\fR [\fB-l\fR | \fB-s\fR] \fIfile1\fR \fIfile2\fR [\fIskip1\fR] [\fIskip2\fR]
.fi

.SH DESCRIPTION
.sp
.LP
\fBcmp\fR compares two files \fIfile1\fR and \fIfile2\fR. \fBcmp\fR writes no output if the files are the same. By default, if the files differ, the byte and line number at which the first difference occurred are written to standard output. Bytes and lines are numbered beginning with \fB1\fR.
.sp
.LP
\fIskip1\fR and \fIskip2\fR are initial byte offsets into \fIfile1\fR and \fIfile2\fR respectively, and can be either octal or decimal. A leading \fB0\fR denotes octal.
.sp
.LP
If either \fIfile1\fR or \fIfiles2\fR is \fB-\fR, \fBcmp\fR uses standard input for that operand.
.SH OPTIONS
.sp
.LP
The following options are supported:
.sp
.ne 2
.mk
.na
\fB\fB-l\fR\fR
.ad
.RS 6n
.rt  
Write the decimal byte number and the differing bytes (in octal) for each difference.
.RE

.sp
.ne 2
.mk
.na
\fB\fB-s\fR\fR
.ad
.RS 6n
.rt  
Write nothing for differing files. Return \fBnon-zero\fR exit status only.
.RE

.SH OPERANDS
.sp
.LP
The following operands are supported:
.sp
.ne 2
.mk
.na
\fB\fIfile1\fR\fR
.ad
.RS 9n
.rt  
A path name of the first file to be compared. If \fIfile1\fR is \fB\(mi\fR, the standard input is used.
.RE

.sp
.ne 2
.mk
.na
\fB\fIfile2\fR\fR
.ad
.RS 9n
.rt  
A path name of the second file to be compared. If \fIfile2\fR is \fB\(mi\fR, the standard input is used.
.RE

.sp
.LP
If both \fIfile1\fR and \fIfile2\fR refer to standard input or refer to the same \fBFIFO\fR special, block special or character special file, an error results.
.SH USAGE
.sp
.LP
See \fBlargefile\fR(5) for the description of the behavior of \fBcmp\fR when encountering files greater than or equal to 2 Gbyte (2^31 bytes).
.SH EXAMPLES
.LP
\fBExample 1 \fRComparing Files Byte for Byte
.sp
.LP
The following example does a byte for byte comparison of \fIfile1\fR and \fIfile2\fR:

.sp
.in +2
.nf
example% cmp file1 file2 0 1024
.fi
.in -2
.sp

.sp
.LP
It skips the first 1024 bytes in \fIfile2\fR before starting the comparison.

.SH ENVIRONMENT VARIABLES
.sp
.LP
See \fBenviron\fR(5) for descriptions of the following environment variables that affect the execution of \fBcmp\fR: \fBLANG\fR, \fBLC_ALL\fR, \fBLC_CTYPE\fR, \fBLC_MESSAGES\fR, and \fBNLSPATH\fR.
.SH EXIT STATUS
.sp
.LP
The following error values are returned:
.sp
.ne 2
.mk
.na
\fB\fB0\fR\fR
.ad
.RS 6n
.rt  
The files are identical.
.RE

.sp
.ne 2
.mk
.na
\fB\fB1\fR\fR
.ad
.RS 6n
.rt  
The files are different. This includes the case where one file is identical to the first part of the other.
.RE

.sp
.ne 2
.mk
.na
\fB\fB>1\fR\fR
.ad
.RS 6n
.rt  
An error occurred.
.RE

.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i) 
lw(2.75i) |lw(2.75i) 
.
ATTRIBUTE TYPEATTRIBUTE VALUE
_
Availabilitysystem/core-os
_
CSIEnabled
_
Interface StabilityCommitted
_
StandardSee \fBstandards\fR(5).
.TE

.SH SEE ALSO
.sp
.LP
\fBcomm\fR(1), \fBdiff\fR(1), \fBattributes\fR(5), \fBenviron\fR(5), \fBlargefile\fR(5), \fBstandards\fR(5)