1 /*- 2 * Copyright (c) 2005 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Andreas Hauser <andy-dragonfly@splashground.de> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * $DragonFly: src/lib/libc/string/strspn.c,v 1.5 2008/05/15 03:48:58 dillon Exp $ 35 */ 36 37 #include <assert.h> 38 #include <limits.h> 39 #include <stdbool.h> 40 #include <string.h> 41 42 /* 43 * Longest initial segment of string *str, containing any chars from *chars. 44 */ 45 size_t 46 strspn(const char *str, const char *chars) 47 { 48 const char *s; 49 bool charset[UCHAR_MAX + 1]; 50 51 _DIAGASSERT(str != NULL); 52 _DIAGASSERT(chars != NULL); 53 54 if(*str == '\0') 55 return 0; 56 if(*chars == '\0') 57 return 0; 58 59 memset(charset, false, sizeof(charset)); 60 for( ; *chars != '\0'; chars++) 61 charset[*(const unsigned char *)chars] = true; 62 63 for(s = str; charset[*(const unsigned char *)s] == true; s++) 64 /* NOTHING */ 65 ; 66 67 return (s - str); 68 } 69