sl@0: /* 
sl@0:  * memcmp.c --
sl@0:  *
sl@0:  *	Source code for the "memcmp" library routine.
sl@0:  *
sl@0:  * Copyright (c) 1998 Sun Microsystems, Inc.
sl@0:  *
sl@0:  * See the file "license.terms" for information on usage and redistribution
sl@0:  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
sl@0:  *
sl@0:  * SCCS: @(#) memcmp.c 1.2 98/01/19 10:48:58
sl@0:  */
sl@0: 
sl@0: #include "tcl.h"
sl@0: #include "tclPort.h"
sl@0: 
sl@0: /*
sl@0:  * Here is the prototype just in case it is not included
sl@0:  * in tclPort.h.
sl@0:  */
sl@0: 
sl@0: int		memcmp _ANSI_ARGS_((CONST VOID *s1,
sl@0: 			    CONST VOID *s2, size_t n));
sl@0: 
sl@0: /*
sl@0:  *----------------------------------------------------------------------
sl@0:  *
sl@0:  * memcmp --
sl@0:  *
sl@0:  *	Compares two bytes sequences.
sl@0:  *
sl@0:  * Results:
sl@0:  *     compares  its  arguments, looking at the first n
sl@0:  *     bytes (each interpreted as an unsigned char), and  returns
sl@0:  *     an integer less than, equal to, or greater than 0, accord-
sl@0:  *     ing as s1 is less  than,  equal  to,  or
sl@0:  *     greater than s2 when taken to be unsigned 8 bit numbers.
sl@0:  *
sl@0:  * Side effects:
sl@0:  *	None.
sl@0:  *
sl@0:  *----------------------------------------------------------------------
sl@0:  */
sl@0: 
sl@0: int
sl@0: memcmp(s1, s2, n)
sl@0:     CONST VOID *s1;			/* First string. */
sl@0:     CONST VOID *s2;			/* Second string. */
sl@0:     size_t      n;                      /* Length to compare. */
sl@0: {
sl@0:     CONST unsigned char *ptr1 = (CONST unsigned char *) s1;
sl@0:     CONST unsigned char *ptr2 = (CONST unsigned char *) s2;
sl@0: 
sl@0:     for ( ; n-- ; ptr1++, ptr2++) {
sl@0: 	unsigned char u1 = *s1, u2 = *s2;
sl@0: 
sl@0: 	if ( u1 != u2) {
sl@0: 	    return (u1-u2);
sl@0: 	}
sl@0:     }
sl@0:     return 0;
sl@0: }