1/* Search character in UTF-8 string. 2 Copyright (C) 1999, 2002, 2006-2007, 2009-2010 Free Software Foundation, 3 Inc. 4 Written by Bruno Haible <bruno@clisp.org>, 2002. 5 6 This program is free software: you can redistribute it and/or modify it 7 under the terms of the GNU Lesser General Public License as published 8 by the Free Software Foundation; either version 3 of the License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Lesser General Public License for more details. 15 16 You should have received a copy of the GNU Lesser General Public License 17 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 18 19#include <config.h> 20 21/* Specification. */ 22#include "unistr.h" 23 24uint8_t * 25u8_strrchr (const uint8_t *s, ucs4_t uc) 26{ 27 /* Calling u8_strlen and then searching from the other end would cause more 28 memory accesses. Avoid that, at the cost of a few more comparisons. */ 29 uint8_t *result = NULL; 30 uint8_t c[6]; 31 32 if (uc < 0x80) 33 { 34 uint8_t c0 = uc; 35 36 for (;; s++) 37 { 38 if (*s == c0) 39 result = (uint8_t *) s; 40 if (*s == 0) 41 break; 42 } 43 } 44 else 45 switch (u8_uctomb_aux (c, uc, 6)) 46 { 47 case 2: 48 if (*s) 49 { 50 uint8_t c0 = c[0]; 51 uint8_t c1 = c[1]; 52 53 /* FIXME: Maybe walking the string via u8_mblen is a win? */ 54 for (;; s++) 55 { 56 if (s[1] == 0) 57 break; 58 if (*s == c0 && s[1] == c1) 59 result = (uint8_t *) s; 60 } 61 } 62 break; 63 64 case 3: 65 if (*s && s[1]) 66 { 67 uint8_t c0 = c[0]; 68 uint8_t c1 = c[1]; 69 uint8_t c2 = c[2]; 70 71 /* FIXME: Maybe walking the string via u8_mblen is a win? */ 72 for (;; s++) 73 { 74 if (s[2] == 0) 75 break; 76 if (*s == c0 && s[1] == c1 && s[2] == c2) 77 result = (uint8_t *) s; 78 } 79 } 80 break; 81 82 case 4: 83 if (*s && s[1] && s[2]) 84 { 85 uint8_t c0 = c[0]; 86 uint8_t c1 = c[1]; 87 uint8_t c2 = c[2]; 88 uint8_t c3 = c[3]; 89 90 /* FIXME: Maybe walking the string via u8_mblen is a win? */ 91 for (;; s++) 92 { 93 if (s[3] == 0) 94 break; 95 if (*s == c0 && s[1] == c1 && s[2] == c2 && s[3] == c3) 96 result = (uint8_t *) s; 97 } 98 } 99 break; 100 } 101 return result; 102} 103