lib/libc/stdio/fwide.c

   1 /* $NetBSD: fwide.c,v 1.3 2005/06/12 05:21:27 lukem Exp $ */
   2
   3 /*-
   4  * Copyright (c)2001 Citrus Project,
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  *
  28  * $Citrus$
  29  */
  30
  31 #include <sys/cdefs.h>
  32 #if defined(LIBC_SCCS) && !defined(lint)
  33 __RCSID("$NetBSD: fwide.c,v 1.3 2005/06/12 05:21:27 lukem Exp $");
  34 #endif /* LIBC_SCCS and not lint */
  35
  36 #include <assert.h>
  37 #include <stdio.h>
  38 #include <wchar.h>
  39 #include "reentrant.h"
  40 #include "local.h"
  41
  42 int
  43 fwide(FILE *fp, int mode)
  44 {
  45         struct wchar_io_data *wcio;
  46
  47         _DIAGASSERT(fp != NULL);
  48
  49         /*
  50          * this implementation use only -1, 0, 1
  51          * for mode value.
  52          * (we don't need to do this, but
  53          *  this can make things simpler.)
  54          */
  55         if (mode > 0)
  56                 mode = 1;
  57         else if (mode < 0)
  58                 mode = -1;
  59
  60         FLOCKFILE(fp);
  61         wcio = WCIO_GET(fp);
  62         if (!wcio)
  63                 return 0; /* XXX */
  64
  65         if (wcio->wcio_mode == 0 && mode != 0)
  66                 wcio->wcio_mode = mode;
  67         else
  68                 mode = wcio->wcio_mode;
  69         FUNLOCKFILE(fp);
  70
  71         return mode;
  72 }