1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved. 24 */ 25 26 /* Copyright (c) 1988 AT&T */ 27 /* All Rights Reserved */ 28 29 #include "lint.h" 30 #include <string.h> 31 #include <stddef.h> 32 #include <sys/types.h> 33 34 /* 35 * strstr() locates the first occurrence in the string as1 of 36 * the sequence of characters (excluding the terminating null 37 * character) in the string as2. strstr() returns a pointer 38 * to the located string, or a null pointer if the string is 39 * not found. If as2 is empty, the function returns as1. 40 */ 41 42 char * 43 strstr(const char *as1, const char *as2) 44 { 45 const char *s1, *s2; 46 const char *tptr; 47 char c; 48 49 s1 = as1; 50 s2 = as2; 51 52 if (s2 == NULL || *s2 == '\0') 53 return ((char *)s1); 54 55 c = *s2; 56 while (*s1 != '\0') { 57 if (c == *s1++) { 58 tptr = s1; 59 while ((c = *++s2) == *s1++ && c != '\0') 60 continue; 61 if (c == '\0') 62 return ((char *)tptr - 1); 63 s1 = tptr; 64 s2 = as2; 65 c = *s2; 66 } 67 } 68 69 return (NULL); 70 } 71 72 /* 73 * strnstr() locates the first occurrence in the string as1 of 74 * the sequence of characters (excluding the terminating null 75 * character) in the string as2, where not more than n characters 76 * from the string as1 are searched. strnstr() returns a pointer 77 * to the located string, or a null pointer if the string is 78 * not found. If as2 is empty, the function returns as1. 79 */ 80 81 char * 82 strnstr(const char *as1, const char *as2, size_t n) 83 { 84 const char *s1, *s2; 85 const char *tptr; 86 size_t k; 87 char c; 88 89 s1 = as1; 90 s2 = as2; 91 92 if (s2 == NULL || *s2 == '\0') 93 return ((char *)s1); 94 95 c = *s2; 96 while (*s1 != '\0' && n--) { 97 if (c == *s1++) { 98 k = n; 99 tptr = s1; 100 while ((c = *++s2) == *s1++ && c != '\0' && k--) 101 continue; 102 if (c == '\0') 103 return ((char *)tptr - 1); 104 s1 = tptr; 105 s2 = as2; 106 c = *s2; 107 } 108 } 109 110 return (NULL); 111 } 112