strstr.c

操作系统SunOS 4.1.3版本的源码

#if !defined(lint) && defined(SCCSIDS)
static	char sccsid[] = "@(#)strstr.c 1.1 92/07/30 SMI"; /* from UCB 4.1 80/12/21 */
#endif

/*
 * Get matching substring
 */

char *
strstr(s1, s2)
	register char *s1, *s2;
{
	int s2len = strlen(s2);	/* length of the second string */
	/*
	 * If the length of the second string is 0, 
	 *  return the first argument.
	 */
	if (s2len == 0)
		return (s1);

	while (strlen(s1) >= s2len) { 
		if (strncmp(s1, s2, s2len) == 0)
			return (s1);
		s1++;
	}
	return (0);
}