1 /* 2 * Copyright (c) 1989 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that the above copyright notice and this paragraph are 7 * duplicated in all such forms and that any documentation, 8 * advertising materials, and other materials related to such 9 * distribution and use acknowledge that the software was developed 10 * by the University of California, Berkeley. The name of the 11 * University may not be used to endorse or promote products derived 12 * from this software without specific prior written permission. 13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 16 */ 17 18 #if defined(LIBC_SCCS) && !defined(lint) 19 static char sccsid[] = "@(#)strncmp.c 5.4 (Berkeley) 05/17/90"; 20 #endif /* LIBC_SCCS and not lint */ 21 22 #include <sys/stdc.h> 23 #include <string.h> 24 25 int 26 strncmp(s1, s2, n) 27 register const char *s1, *s2; 28 register size_t n; 29 { 30 31 if (n == 0) 32 return (0); 33 do { 34 if (*s1 != *s2++) 35 return (*(unsigned char *)s1 - *(unsigned char *)--s2); 36 if (*s1++ == 0) 37 break; 38 } while (--n != 0); 39 return (0); 40 } 41