blob: fab36e3fb3d4e1c534890ad04b34f1f5b5fd02a6 [file] [log] [blame]
/* Simple implementation of strstr for systems without it.
This function is in the public domain. */
strstr -- locate first occurance of a substring
#include <string.h>
char *strstr (char *s1, char *s2)
Locates the first occurance in the string pointed to by S1 of
the string pointed to by S2. Returns a pointer to the substring
found, or a NULL pointer if not found. If S2 points to a string
with zero length, the function returns S1.
/* FIXME: The above description is ANSI compiliant. This routine has not
been validated to comply with it. -fnf */
char *
strstr (s1, s2)
char *s1, *s2;
register char *p = s1;
extern char *strchr ();
extern int strncmp ();
#if __GNUC__==2
extern __SIZE_TYPE__ strlen ();
register int len = strlen (s2);
for (; (p = strchr (p, *s2)) != 0; p++)
if (strncmp (p, s2, len) == 0)
return (p);
return (0);