stdio/FreeBSD/ungetwc.c

   1 /*-
   2  * Copyright (c) 2002-2004 Tim J. Robbins.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD: src/lib/libc/stdio/ungetwc.c,v 1.9 2004/07/20 08:27:27 tjr Exp $");
  29
  30 #include "namespace.h"
  31 #include <errno.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <wchar.h>
  35 #include "un-namespace.h"
  36 #include "libc_private.h"
  37 #include "local.h"
  38 #include "mblocal.h"
  39
  40 /*
  41  * Non-MT-safe version.
  42  */
  43 wint_t
  44 __ungetwc(wint_t wc, FILE *fp)
  45 {
  46         char buf[MB_LEN_MAX];
  47         size_t len;
  48
  49         if (wc == WEOF)
  50                 return (WEOF);
  51         if ((len = __wcrtomb(buf, wc, &fp->_extra->mbstate)) == (size_t)-1) {
  52                 fp->_flags |= __SERR;
  53                 return (WEOF);
  54         }
  55         while (len-- != 0)
  56                 if (__ungetc((unsigned char)buf[len], fp) == EOF)
  57                         return (WEOF);
  58
  59         return (wc);
  60 }
  61
  62 /*
  63  * MT-safe version.
  64  */
  65 wint_t
  66 ungetwc(wint_t wc, FILE *fp)
  67 {
  68         wint_t r;
  69
  70         FLOCKFILE(fp);
  71         ORIENT(fp, 1);
  72         r = __ungetwc(wc, fp);
  73         FUNLOCKFILE(fp);
  74
  75         return (r);
  76 }