Open64: osprey/cygnus/libiberty/strstr.c Source File

00001 /* Simple implementation of strstr for systems without it.
00002    This function is in the public domain.  */
00003 
00004 /*
00005 
00006 @deftypefn Supplemental char* strstr (const char *@var{string}, const char *@var{sub})
00007 
00008 This function searches for the substring @var{sub} in the string
00009 @var{string}, not including the terminating null characters.  A pointer
00010 to the first occurrence of @var{sub} is returned, or @code{NULL} if the
00011 substring is absent.  If @var{sub} points to a string with zero
00012 length, the function returns @var{string}.
00013 
00014 @end deftypefn
00015 
00016 
00017 */
00018 
00019 
00020 /* FIXME:  The above description is ANSI compiliant.  This routine has not
00021    been validated to comply with it.  -fnf */
00022 
00023 char *
00024 strstr (s1, s2)
00025   char *s1, *s2;
00026 {
00027   register char *p = s1;
00028   extern char *strchr ();
00029   extern int strncmp ();
00030 #if __GNUC__ >= 2
00031   extern __SIZE_TYPE__ strlen (const char *);
00032 #endif
00033   register int len = strlen (s2);
00034 
00035   for (; (p = strchr (p, *s2)) != 0; p++)
00036     {
00037       if (strncmp (p, s2, len) == 0)
00038   {
00039     return (p);
00040   }
00041     }
00042   return (0);
00043 }