firmware/common/strstr.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id: $
   9  *
  10  * Copyright (C) 1991, 1992  Linus Torvalds
  11  * (from linux/lib/string.c)
  12  *
  13  ****************************************************************************/
  14
  15 #include <string.h>
  16
  17 /**
  18  * strstr - Find the first substring in a %NUL terminated string
  19  * @s1: The string to be searched
  20  * @s2: The string to search for
  21  */
  22 char *strstr(const char *s1, const char *s2)
  23 {
  24     int l1, l2;
  25
  26     l2 = strlen(s2);
  27     if (!l2)
  28         return (char *)s1;
  29     l1 = strlen(s1);
  30     while (l1 >= l2) {
  31         l1--;
  32         if (!memcmp(s1, s2, l2))
  33             return (char *)s1;
  34         s1++;
  35     }
  36     return NULL;
  37 }
  38