compilers/bcc/linux86-0.16.17/libc/string/strstr.c

   1 /* Copyright (C) 1995,1996 Robert de Bath <rdebath@cix.compulink.co.uk>
   2  * This file is part of the Linux-8086 C library and is distributed
   3  * under the GNU Library General Public License.
   4  */
   5
   6 #include <string.h>
   7
   8 #if 1
   9 /* We've now got a nice fast strchr and memcmp use them */
  10
  11 char *
  12 strstr(s1, s2)
  13 char *s1; char *s2;
  14 {
  15    register int l = strlen(s2);
  16    register char * p = s1;
  17
  18    if( l==0 ) return p;
  19
  20    while (p = strchr(p, *s2))
  21    {
  22       if( memcmp(p, s2, l) == 0 )
  23          return p;
  24       p++;
  25    }
  26    return (char *) 0;
  27 }
  28
  29 #else
  30 /* This is a nice simple self contained strstr,
  31    now go and work out why the GNU one is faster :-) */
  32
  33 char *strstr(str1, str2)
  34 char *str1, *str2;
  35 {
  36     register char *Sptr, *Tptr;
  37     int len = strlen(str1) -strlen(str2) + 1;
  38
  39     if (*str2)
  40         for (; len > 0; len--, str1++){
  41             if (*str1 != *str2)
  42                 continue;
  43
  44             for (Sptr = str1, Tptr = str2; *Tptr != '\0'; Sptr++, Tptr++)
  45                 if (*Sptr != *Tptr)
  46                     break;
  47
  48             if (*Tptr == '\0')
  49                 return (char*) str1;
  50         }
  51
  52     return (char*)0;
  53 }
  54 #endif