1 /* Compare at most N characters of two strings without taking care for 2 the case. 3 Copyright (C) 1992, 1996, 1997 Free Software Foundation, Inc. 4 5 NOTE: The canonical source of this file is maintained with the GNU C Library. 6 Bugs can be reported to bug-glibc@prep.ai.mit.edu. 7 8 This program is free software; you can redistribute it and/or modify it 9 under the terms of the GNU General Public License as published by the 10 Free Software Foundation; either version 2, or (at your option) any 11 later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program; if not, write to the Free Software 20 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 21 USA. */ 22 23 #ifdef HAVE_CONFIG_H 24 # include <config.h> 25 #endif 26 #ifdef HAVE_SUPPORT_H 27 # include "support.h" 28 #endif 29 30 #ifdef HAVE_STRING_H 31 # include <string.h> 32 #endif 33 34 #include <ctype.h> 35 36 #ifndef weak_alias 37 # define __strncasecmp strncasecmp 38 # define TOLOWER(Ch) tolower (Ch) 39 #else 40 # ifdef USE_IN_EXTENDED_LOCALE_MODEL 41 # define __strncasecmp __strncasecmp_l 42 # define TOLOWER(Ch) __tolower_l ((Ch), loc) 43 # else 44 # define TOLOWER(Ch) tolower (Ch) 45 # endif 46 #endif 47 48 #ifdef USE_IN_EXTENDED_LOCALE_MODEL 49 # define LOCALE_PARAM , loc 50 # define LOCALE_PARAM_DECL __locale_t loc; 51 #else 52 # define LOCALE_PARAM 53 # define LOCALE_PARAM_DECL 54 #endif 55 56 /* Compare no more than N characters of S1 and S2, 57 ignoring case, returning less than, equal to or 58 greater than zero if S1 is lexicographically less 59 than, equal to or greater than S2. */ 60 int 61 __strncasecmp (s1, s2, n LOCALE_PARAM) 62 const char *s1; 63 const char *s2; 64 size_t n; 65 LOCALE_PARAM_DECL 66 { 67 const unsigned char *p1 = (const unsigned char *) s1; 68 const unsigned char *p2 = (const unsigned char *) s2; 69 unsigned char c1, c2; 70 71 if (p1 == p2 || n == 0) 72 return 0; 73 74 do 75 { 76 c1 = TOLOWER (*p1++); 77 c2 = TOLOWER (*p2++); 78 if (c1 == '\0' || c1 != c2) 79 return c1 - c2; 80 } while (--n > 0); 81 82 return c1 - c2; 83 } 84 #ifndef __strncasecmp 85 weak_alias (__strncasecmp, strncasecmp) 86 #endif 87