1 /* Case-insensitive buffer comparator. 2 Copyright (C) 1996-1997, 2000, 2003, 2006, 2009-2021 Free Software 3 Foundation, Inc. 4 5 This program is free software: you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 17 18 /* Written by Jim Meyering. */ 19 20 #include <config.h> 21 22 #include "memcasecmp.h" 23 24 #include <ctype.h> 25 #include <limits.h> 26 27 /* Like memcmp, but ignore differences in case. 28 Convert to upper case (not lower) before comparing so that 29 join -i works with sort -f. */ 30 31 int 32 memcasecmp (const void *vs1, const void *vs2, size_t n) /* */ 33 { 34 size_t i; 35 char const *s1 = vs1; 36 char const *s2 = vs2; 37 for (i = 0; i < n; i++) 38 { 39 unsigned char u1 = s1[i]; 40 unsigned char u2 = s2[i]; 41 int U1 = toupper (u1); 42 int U2 = toupper (u2); 43 int diff = (UCHAR_MAX <= INT_MAX ? U1 - U2 : _GL_CMP (U1, U2)); 44 if (diff) 45 return diff; 46 } 47 return 0; 48 }