1/* Search character in piece of 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_chr (const uint8_t *s, size_t n, ucs4_t uc) 26{ 27 uint8_t c[6]; 28 29 if (uc < 0x80) 30 { 31 uint8_t c0 = uc; 32 33 for (; n > 0; s++, n--) 34 { 35 if (*s == c0) 36 return (uint8_t *) s; 37 } 38 } 39 else 40 switch (u8_uctomb_aux (c, uc, 6)) 41 { 42 case 2: 43 if (n > 1) 44 { 45 uint8_t c0 = c[0]; 46 uint8_t c1 = c[1]; 47 48 for (n--; n > 0; s++, n--) 49 { 50 if (*s == c0 && s[1] == c1) 51 return (uint8_t *) s; 52 } 53 } 54 break; 55 56 case 3: 57 if (n > 2) 58 { 59 uint8_t c0 = c[0]; 60 uint8_t c1 = c[1]; 61 uint8_t c2 = c[2]; 62 63 for (n -= 2; n > 0; s++, n--) 64 { 65 if (*s == c0 && s[1] == c1 && s[2] == c2) 66 return (uint8_t *) s; 67 } 68 } 69 break; 70 71 case 4: 72 if (n > 3) 73 { 74 uint8_t c0 = c[0]; 75 uint8_t c1 = c[1]; 76 uint8_t c2 = c[2]; 77 uint8_t c3 = c[3]; 78 79 for (n -= 3; n > 0; s++, n--) 80 { 81 if (*s == c0 && s[1] == c1 && s[2] == c2 && s[3] == c3) 82 return (uint8_t *) s; 83 } 84 } 85 break; 86 } 87 return NULL; 88} 89