usr/src/lib/libc/port/i18n/wcswcs.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 (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1986 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 /*
  33  * Returns a pointer to the first occurrnce of ws1 in ws2.
  34  */
  35
  36 #pragma weak _wcswcs = wcswcs
  37
  38 #include "lint.h"
  39 #include <stdlib.h>
  40
  41 wchar_t *
  42 wcswcs(const wchar_t *ws1, const wchar_t *ws2)
  43 {
  44         const wchar_t *s1, *s2;
  45         const wchar_t *tptr;
  46         wchar_t c;
  47
  48         s1 = ws1;
  49         s2 = ws2;
  50
  51         if (s2 == NULL || *s2 == 0)
  52                 return ((wchar_t *)s1);
  53         c = *s2;
  54
  55         while (*s1)
  56                 if (*s1++ == c) {
  57                         tptr = s1;
  58                         while ((c = *++s2) == *s1++ && c)
  59                                 ;
  60                         if (c == 0)
  61                                 return ((wchar_t *)tptr - 1);
  62                         s1 = tptr;
  63                         s2 = ws2;
  64                         c = *s2;
  65                 }
  66         return (NULL);
  67 }