/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
*/
/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
#include "lint.h"
#include <string.h>
#include <stddef.h>
#include <sys/types.h>
/*
* strstr() locates the first occurrence in the string as1 of
* the sequence of characters (excluding the terminating null
* character) in the string as2. strstr() returns a pointer
* to the located string, or a null pointer if the string is
* not found. If as2 is empty, the function returns as1.
*/
char *
strstr(const char *as1, const char *as2)
{
const char *s1, *s2;
const char *tptr;
char c;
s1 = as1;
s2 = as2;
if (s2 == NULL || *s2 == '\0')
return ((char *)s1);
c = *s2;
while (*s1 != '\0') {
if (c == *s1++) {
tptr = s1;
while ((c = *++s2) == *s1++ && c != '\0')
continue;
if (c == '\0')
return ((char *)tptr - 1);
s1 = tptr;
s2 = as2;
c = *s2;
}
}
return (NULL);
}
/*
* strnstr() locates the first occurrence in the string as1 of
* the sequence of characters (excluding the terminating null
* character) in the string as2, where not more than n characters
* from the string as1 are searched. strnstr() returns a pointer
* to the located string, or a null pointer if the string is
* not found. If as2 is empty, the function returns as1.
*/
char *
strnstr(const char *as1, const char *as2, size_t n)
{
const char *s1, *s2;
const char *tptr;
size_t k;
char c;
s1 = as1;
s2 = as2;
if (s2 == NULL || *s2 == '\0')
return ((char *)s1);
c = *s2;
while (*s1 != '\0' && n--) {
if (c == *s1++) {
k = n;
tptr = s1;
while ((c = *++s2) == *s1++ && c != '\0' && k--)
continue;
if (c == '\0')
return ((char *)tptr - 1);
s1 = tptr;
s2 = as2;
c = *s2;
}
}
return (NULL);
}