1/* Simple implementation of strstr for systems without it.
2   This function is in the public domain.  */
3
4/*
5
6NAME
7
8	strstr -- locate first occurance of a substring
9
10SYNOPSIS
11
12	#include <string.h>
13
14	char *strstr (char *s1, char *s2)
15
16DESCRIPTION
17
18	Locates the first occurance in the string pointed to by S1 of
19	the string pointed to by S2.  Returns a pointer to the substring
20	found, or a NULL pointer if not found.  If S2 points to a string
21	with zero length, the function returns S1.
22
23BUGS
24
25*/
26
27
28/* FIXME:  The above description is ANSI compiliant.  This routine has not
29   been validated to comply with it.  -fnf */
30
31char *
32strstr (s1, s2)
33  char *s1, *s2;
34{
35  register char *p = s1;
36  extern char *strchr ();
37  extern int strncmp ();
38#if __GNUC__==2
39  extern __SIZE_TYPE__ strlen ();
40#endif
41  register int len = strlen (s2);
42
43  for (; (p = strchr (p, *s2)) != 0; p++)
44    {
45      if (strncmp (p, s2, len) == 0)
46	{
47	  return (p);
48	}
49    }
50  return (0);
51}
52