1.\" Copyright (c) 1990, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" Chris Torek. 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)bcmp.3 8.1 (Berkeley) 6/4/93 31.\" $FreeBSD$ 32.\" 33.Dd August 15, 2016 34.Dt BCMP 3 35.Os 36.Sh NAME 37.Nm bcmp 38.Nd compare byte string 39.Sh LIBRARY 40.Lb libc 41.Sh SYNOPSIS 42.In strings.h 43.Ft int 44.Fn bcmp "const void *b1" "const void *b2" "size_t len" 45.Sh DESCRIPTION 46The 47.Fn bcmp 48function 49compares byte string 50.Fa b1 51against byte string 52.Fa b2 , 53returning zero if they are identical, non-zero otherwise. 54Both strings are assumed to be 55.Fa len 56bytes long. 57Zero-length strings are always identical. 58.Pp 59The strings may overlap. 60.Sh SEE ALSO 61.Xr memcmp 3 , 62.Xr strcasecmp 3 , 63.Xr strcmp 3 , 64.Xr strcoll 3 , 65.Xr strxfrm 3 , 66.Xr timingsafe_bcmp 3 67.Sh HISTORY 68A 69.Fn bcmp 70function first appeared in 71.Bx 4.2 . 72Its prototype existed previously in 73.In string.h 74before it was moved to 75.In strings.h 76for 77.St -p1003.1-2001 78compliance. 79