strstr - find substring in string

Syntax	#include <string.h> char *strstr(const char *s1, const char *s2);
Description	strstr() searches for the first occurrence of string s2 (without the terminating null byte) in string s1.
Return val.	Pointer to the start of the string found in s1
		if successful.
	Null pointer	if s2 is not contained in s1.
	Pointer to the start of s1
		if s2 has a length of 0.
Notes	Strings terminated with the null byte (\0) are expected as arguments.
See also	strchr(), string.h.