source/stristr.c

   1 /*
   2  * OpenBOR - http://www.LavaLit.com
   3  * -----------------------------------------------------------------------
   4  * Licensed under the BSD license, see LICENSE in OpenBOR root for details.
   5  *
   6  * Copyright (c) 2004 - 2011 OpenBOR Team
   7  */
   8
   9 #include <stdio.h>
  10 #include <string.h>
  11 #include <ctype.h>
  12
  13 char *stristr(const char *String, const char *Pattern) {
  14         char *pptr, *sptr, *start;
  15         unsigned int slen, plen;
  16         for(start = (char *) String, pptr = (char *) Pattern, slen = strlen(String), plen = strlen(Pattern);
  17             slen >= plen; start++, slen--) {
  18                 /* find start of pattern in string */
  19                 while(toupper((int) *start) != toupper((int) *Pattern)) {
  20                         start++;
  21                         slen--;
  22                         /* if pattern longer than string */
  23                         if(slen < plen)
  24                                 return (NULL);
  25                 }
  26                 sptr = start;
  27                 pptr = (char *) Pattern;
  28                 while(toupper((int) *sptr) == toupper((int) *pptr)) {
  29                         sptr++;
  30                         pptr++;
  31                         /* if end of pattern then pattern was found */
  32                         if('\0' == *pptr)
  33                                 return (start);
  34                 }
  35         }
  36         return (NULL);
  37 }