usr/src/lib/libc/port/i18n/wcsstr.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include "lint.h"
  30 #include <sys/types.h>
  31 #include <wchar.h>
  32 #include "libc.h"
  33
  34 wchar_t *
  35 wcsstr(const wchar_t *ws1, const wchar_t *ws2)
  36 {
  37         const wchar_t   *os1, *os2;
  38         const wchar_t   *tptr;
  39         wchar_t c;
  40
  41         os1 = ws1;
  42         os2 = ws2;
  43
  44         if (os1 == NULL || *os2 == L'\0')
  45                 return ((wchar_t *)os1);
  46         c = *os2;
  47
  48         while (*os1)
  49                 if (*os1++ == c) {
  50                         tptr = os1;
  51                         while (((c = *++os2) == *os1++) && (c != L'\0'))
  52                                 ;
  53                         if (c == L'\0')
  54                                 return ((wchar_t *)tptr - 1);
  55                         os1 = tptr;
  56                         os2 = ws2;
  57                         c = *os2;
  58                 }
  59         return (NULL);
  60 }