xref: /freebsd/lib/libc/stdio/fgetwc.c (revision 0b7bc80226a5e70af58cce04b29957d71786e835)
1e74101e4STim J. Robbins /*-
2e74101e4STim J. Robbins  * Copyright (c) 2002 Tim J. Robbins.
3e74101e4STim J. Robbins  * All rights reserved.
4e74101e4STim J. Robbins  *
5e74101e4STim J. Robbins  * Redistribution and use in source and binary forms, with or without
6e74101e4STim J. Robbins  * modification, are permitted provided that the following conditions
7e74101e4STim J. Robbins  * are met:
8e74101e4STim J. Robbins  * 1. Redistributions of source code must retain the above copyright
9e74101e4STim J. Robbins  *    notice, this list of conditions and the following disclaimer.
10e74101e4STim J. Robbins  * 2. Redistributions in binary form must reproduce the above copyright
11e74101e4STim J. Robbins  *    notice, this list of conditions and the following disclaimer in the
12e74101e4STim J. Robbins  *    documentation and/or other materials provided with the distribution.
13e74101e4STim J. Robbins  *
14e74101e4STim J. Robbins  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15e74101e4STim J. Robbins  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16e74101e4STim J. Robbins  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17e74101e4STim J. Robbins  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18e74101e4STim J. Robbins  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19e74101e4STim J. Robbins  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20e74101e4STim J. Robbins  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21e74101e4STim J. Robbins  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22e74101e4STim J. Robbins  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23e74101e4STim J. Robbins  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24e74101e4STim J. Robbins  * SUCH DAMAGE.
25e74101e4STim J. Robbins  */
26e74101e4STim J. Robbins 
27e74101e4STim J. Robbins #include <sys/cdefs.h>
28e74101e4STim J. Robbins __FBSDID("$FreeBSD$");
29e74101e4STim J. Robbins 
30e74101e4STim J. Robbins #include "namespace.h"
31e74101e4STim J. Robbins #include <errno.h>
32e74101e4STim J. Robbins #include <stdio.h>
3324990dfaSTim J. Robbins #include <stdlib.h>
34e74101e4STim J. Robbins #include <wchar.h>
35e74101e4STim J. Robbins #include "un-namespace.h"
36e74101e4STim J. Robbins #include "libc_private.h"
37e74101e4STim J. Robbins #include "local.h"
38e74101e4STim J. Robbins 
390b7bc802STim J. Robbins static __inline wint_t	__fgetwc_nbf(FILE *);
400b7bc802STim J. Robbins 
41e74101e4STim J. Robbins wint_t
42e74101e4STim J. Robbins fgetwc(FILE *fp)
43e74101e4STim J. Robbins {
440b7bc802STim J. Robbins 	wint_t wc;
450b7bc802STim J. Robbins 
460b7bc802STim J. Robbins 	FLOCKFILE(fp);
470b7bc802STim J. Robbins 	ORIENT(fp, 1);
480b7bc802STim J. Robbins 	if (MB_CUR_MAX == 1) {
490b7bc802STim J. Robbins 		/*
500b7bc802STim J. Robbins 		 * Assume we're using a single-byte locale. A safer test
510b7bc802STim J. Robbins 		 * might be to check _CurrentRuneLocale->encoding.
520b7bc802STim J. Robbins 		 */
530b7bc802STim J. Robbins 		wc = (wint_t)__sgetc(fp);
540b7bc802STim J. Robbins 	} else
550b7bc802STim J. Robbins 		wc = __fgetwc_nbf(fp);
560b7bc802STim J. Robbins 	FUNLOCKFILE(fp);
570b7bc802STim J. Robbins 
580b7bc802STim J. Robbins 	return (wc);
590b7bc802STim J. Robbins }
600b7bc802STim J. Robbins 
610b7bc802STim J. Robbins static __inline wint_t
620b7bc802STim J. Robbins __fgetwc_nbf(FILE *fp)
630b7bc802STim J. Robbins {
6424990dfaSTim J. Robbins 	char buf[MB_LEN_MAX];
6524990dfaSTim J. Robbins 	mbstate_t mbs;
6624990dfaSTim J. Robbins 	size_t n, nconv;
6724990dfaSTim J. Robbins 	int c;
6824990dfaSTim J. Robbins 	wchar_t wc;
69e74101e4STim J. Robbins 
7024990dfaSTim J. Robbins 	n = 0;
7124990dfaSTim J. Robbins 	while (n < MB_CUR_MAX) {
720b7bc802STim J. Robbins 		if ((c = __sgetc(fp)) == EOF) {
7324990dfaSTim J. Robbins 			if (n == 0)
7424990dfaSTim J. Robbins 				return (WEOF);
7524990dfaSTim J. Robbins 			break;
7624990dfaSTim J. Robbins 		}
7724990dfaSTim J. Robbins 		buf[n++] = (char)c;
7824990dfaSTim J. Robbins 		memset(&mbs, 0, sizeof(mbs));
7924990dfaSTim J. Robbins 		nconv = mbrtowc(&wc, buf, n, &mbs);
8024990dfaSTim J. Robbins 		if (nconv == n)
81e74101e4STim J. Robbins 			return (wc);
8224990dfaSTim J. Robbins 		else if (nconv == 0)
8324990dfaSTim J. Robbins 			return (L'\0');
84bddc6280STim J. Robbins 		else if (nconv == (size_t)-1)
8524990dfaSTim J. Robbins 			break;
8624990dfaSTim J. Robbins 	}
8724990dfaSTim J. Robbins 
880b7bc802STim J. Robbins 	FUNLOCKFILE(fp);
8924990dfaSTim J. Robbins 	while (n-- != 0)
9024990dfaSTim J. Robbins 		ungetc((unsigned char)buf[n], fp);
910b7bc802STim J. Robbins 	FLOCKFILE(fp);
9224990dfaSTim J. Robbins 	errno = EILSEQ;
9324990dfaSTim J. Robbins 	return (WEOF);
94e74101e4STim J. Robbins }
95