lib/libc/stdio/fgetwc.c

   1 /* $NetBSD: fgetwc.c,v 1.13 2012/03/15 18:22:30 christos 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: fgetwc.c,v 1.13 2012/03/15 18:22:30 christos Exp $");
  34 #endif /* LIBC_SCCS and not lint */
  35
  36 #include <assert.h>
  37 #include <errno.h>
  38 #include <stdio.h>
  39 #include <wchar.h>
  40 #include "reentrant.h"
  41 #include "local.h"
  42
  43 wint_t
  44 __fgetwc_unlock(FILE *fp)
  45 {
  46         struct wchar_io_data *wcio;
  47         wchar_t wc;
  48         size_t nr;
  49
  50         _DIAGASSERT(fp != NULL);
  51
  52         _SET_ORIENTATION(fp, 1);
  53         wcio = WCIO_GET(fp);
  54         _DIAGASSERT(wcio != NULL);
  55
  56         /* if there're ungetwc'ed wchars, use them */
  57         if (wcio->wcio_ungetwc_inbuf)
  58                 return wcio->wcio_ungetwc_buf[--wcio->wcio_ungetwc_inbuf];
  59
  60         if (fp->_r <= 0) {
  61 restart:
  62                 if (__srefill(fp) != 0)
  63                         return WEOF;
  64         }
  65         nr = mbrtowc(&wc, (const char *)fp->_p,
  66             (size_t)fp->_r, &wcio->wcio_mbstate_in);
  67         if (nr == (size_t)-1) {
  68                 fp->_flags |= __SERR;
  69                 return WEOF;
  70         } else if (nr == (size_t)-2) {
  71                 fp->_p += fp->_r;
  72                 fp->_r = 0;
  73                 goto restart;
  74         }
  75         if (wc == L'\0') {
  76                 while (*fp->_p != '\0') {
  77                         ++fp->_p;
  78                         --fp->_r;
  79                 }
  80                 nr = 1;
  81         }
  82         fp->_p += nr;
  83         _DIAGASSERT(__type_fit(int, fp->_r - nr));
  84         fp->_r -= (int)nr;
  85
  86         return wc;
  87 }
  88
  89 wint_t
  90 fgetwc(FILE *fp)
  91 {
  92         wint_t r;
  93
  94         _DIAGASSERT(fp != NULL);
  95
  96         FLOCKFILE(fp);
  97         r = __fgetwc_unlock(fp);
  98         FUNLOCKFILE(fp);
  99
 100         return r;
 101 }
 102