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fgetwc.c revision 1.4 
      1 /* $NetBSD: fgetwc.c,v 1.4 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: fgetwc.c,v 1.4 2005/06/12 05:21:27 lukem 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 	mbstate_t *st;
     48 	wchar_t wc;
     49 	size_t size;
     50 
     51 	_DIAGASSERT(fp != NULL);
     52 
     53 	_SET_ORIENTATION(fp, 1);
     54 	wcio = WCIO_GET(fp);
     55 	if (wcio == 0) {
     56 		errno = ENOMEM;
     57 		return WEOF;
     58 	}
     59 
     60 	/* if there're ungetwc'ed wchars, use them */
     61 	if (wcio->wcio_ungetwc_inbuf) {
     62 		wc = wcio->wcio_ungetwc_buf[--wcio->wcio_ungetwc_inbuf];
     63 
     64 		return wc;
     65 	}
     66 
     67 	st = &wcio->wcio_mbstate_in;
     68 
     69 	do {
     70 		char c;
     71 		int ch = __sgetc(fp);
     72 
     73 		if (ch == EOF) {
     74 			return WEOF;
     75 		}
     76 
     77 		c = ch;
     78 		size = mbrtowc(&wc, &c, 1, st);
     79 		if (size == (size_t)-1) {
     80 			errno = EILSEQ;
     81 			return WEOF;
     82 		}
     83 	} while (size == (size_t)-2);
     84 
     85 	_DIAGASSERT(size == 1);
     86 
     87 	return wc;
     88 }
     89 
     90 wint_t
     91 fgetwc(FILE *fp)
     92 {
     93 	wint_t r;
     94 
     95 	_DIAGASSERT(fp != NULL);
     96 
     97 	FLOCKFILE(fp);
     98 	r = __fgetwc_unlock(fp);
     99 	FUNLOCKFILE(fp);
    100 
    101 	return (r);
    102 }
    103 
    104