@deftypefn Supplemental char* strstr (const char *@var{string}, const char *@var{sub})
This function searches for the substring @var{sub} in the string
-@var{string}, not including the terminating NUL characters. A pointer
-to the first occurance of @var{sub} is returned, or NULL if the
+@var{string}, not including the terminating null characters. A pointer
+to the first occurrence of @var{sub} is returned, or @code{NULL} if the
substring is absent. If @var{sub} points to a string with zero
length, the function returns @var{string}.
register char *p = s1;
extern char *strchr ();
extern int strncmp ();
-#if __GNUC__==2
- extern __SIZE_TYPE__ strlen ();
+#if __GNUC__ >= 2
+ extern __SIZE_TYPE__ strlen (const char *);
#endif
register int len = strlen (s2);