strcasecmp.c (2475B)
1 /* 2 * Copyright (c) 1987, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <strings.h> 35 #include <ctype.h> 36 37 typedef unsigned char u_char; 38 39 int 40 strcasecmp(const char *s1, const char *s2) 41 { 42 const u_char 43 *us1 = (const u_char *)s1, 44 *us2 = (const u_char *)s2; 45 46 while (tolower(*us1) == tolower(*us2++)) 47 if (*us1++ == '\0') 48 return (0); 49 return (tolower(*us1) - tolower(*--us2)); 50 } 51 52 int 53 strncasecmp(const char *s1, const char *s2, size_t n) 54 { 55 if (n != 0) { 56 const u_char 57 *us1 = (const u_char *)s1, 58 *us2 = (const u_char *)s2; 59 60 do { 61 if (tolower(*us1) != tolower(*us2++)) 62 return (tolower(*us1) - tolower(*--us2)); 63 if (*us1++ == '\0') 64 break; 65 } while (--n != 0); 66 } 67 return (0); 68 } 69