1.\" Copyright (c) 1990, 1991 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" Chris Torek and the American National Standards Committee X3, 6.\" on Information Processing Systems. 7.\" 8.\" %sccs.include.redist.man% 9.\" 10.\" @(#)memcmp.3 5.5 (Berkeley) 06/29/91 11.\" 12.Dd 13.Dt MEMCMP 3 14.Os 15.Sh NAME 16.Nm memcmp 17.Nd compare byte string 18.Sh SYNOPSIS 19.Fd #include <string.h> 20.Ft int 21.Fn memcmp "const void *b1" "const void *b2" "size_t len" 22.Sh DESCRIPTION 23The 24.Fn memcmp 25function 26compares byte string 27.Fa b1 28against byte string 29.Fa b2 . 30Both strings are assumed to be 31.Fa len 32bytes long. 33.Sh RETURN VALUES 34The 35.Fn memcmp 36function 37returns zero if the the two strings are identical, 38otherwise returns the difference between the first two differing bytes 39(treated as unsigned char values, so that 40.Sq Li \e200 41is greater than 42.Sq Li \&\e0 , 43for example). 44Zero-length strings are always identical. 45.Sh SEE ALSO 46.Xr bcmp 3 , 47.Xr strcasecmp 3 , 48.Xr strcmp 3 , 49.Xr strcoll 3 , 50.Xr strxfrm 3 51.Sh STANDARDS 52The 53.Fn memcmp 54function 55conforms to 56.St -ansiC . 57