lib/libc/stdio/ungetwc.c

   1 /*-
   2  * Copyright (c) 2002-2004 Tim J. Robbins.
   3  * All rights reserved.
   4  *
   5  * Copyright (c) 2011 The FreeBSD Foundation
   6  * All rights reserved.
   7  * Portions of this software were developed by David Chisnall
   8  * under sponsorship from the FreeBSD Foundation.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  * $FreeBSD: head/lib/libc/stdio/ungetwc.c 227753 2011-11-20 14:45:42Z theraven $
  32  */
  33
  34
  35 #include "namespace.h"
  36 #include <errno.h>
  37 #include <limits.h>
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <wchar.h>
  41 #include "un-namespace.h"
  42 #include "libc_private.h"
  43 #include "local.h"
  44 #include "mblocal.h"
  45 #include "xlocale_private.h"
  46
  47 /*
  48  * Non-MT-safe version.
  49  */
  50 wint_t
  51 __ungetwc(wint_t wc, FILE *fp, locale_t locale)
  52 {
  53         char buf[MB_LEN_MAX];
  54         size_t len;
  55         struct xlocale_ctype *l = XLOCALE_CTYPE(locale);
  56         struct wchar_io_data *wcio;
  57         mbstate_t *st;
  58
  59         ORIENT(fp,1);
  60         wcio = WCIO_GET(fp);
  61
  62         if (wc == WEOF)
  63                 return (WEOF);
  64         if (wcio == NULL) {
  65                 return (WEOF);
  66         }
  67         wcio->wcio_ungetwc_inbuf = 0;
  68         st = &wcio->wcio_mbstate_out;
  69         if ((len = l->__wcrtomb(buf, wc, st)) == (size_t)-1) {
  70                 fp->pub._flags |= __SERR;
  71                 return (WEOF);
  72         }
  73         while (len-- != 0)
  74                 if (__ungetc((unsigned char)buf[len], fp) == EOF)
  75                         return (WEOF);
  76
  77         return (wc);
  78 }
  79
  80 /*
  81  * MT-safe version.
  82  */
  83 wint_t
  84 ungetwc_l(wint_t wc, FILE *fp, locale_t locale)
  85 {
  86         wint_t r;
  87         FIX_LOCALE(locale);
  88
  89         FLOCKFILE(fp);
  90         ORIENT(fp, 1);
  91         r = __ungetwc(wc, fp, locale);
  92         FUNLOCKFILE(fp);
  93
  94         return (r);
  95 }
  96 wint_t
  97 ungetwc(wint_t wc, FILE *fp)
  98 {
  99         return ungetwc_l(wc, fp, __get_locale());
 100 }