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      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 
    103