1/*
2 * Taken from Wikipedia, which declared it as "public domain".
3 */
4
5#include <sys/types.h>
6#include <string.h>
7
8
9char *
10strstr(const char *s1, const char *s2)
11{
12    size_t s2len;
13    /* Check for the null s2 case. */
14    if (*s2 == '\0')
15        return (char *) s1;
16    s2len = strlen(s2);
17    for (; (s1 = strchr(s1, *s2)) != NULL; s1++) {
18        if (strncmp(s1, s2, s2len) == 0)
19            return (char *)s1;
20    }
21    return NULL;
22}
23
24