fgetwc.c revision 234799 
1/*-
2 * Copyright (c) 2002-2004 Tim J. Robbins.
3 * All rights reserved.
4 *
5 * Copyright (c) 2011 The FreeBSD Foundation
6 * All rights reserved.
7 * Portions of this software were developed by David Chisnall
8 * under sponsorship from the FreeBSD Foundation.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD: head/lib/libc/stdio/fgetwc.c 234799 2012-04-29 16:28:39Z das $");
34
35#include "namespace.h"
36#include <errno.h>
37#include <stdio.h>
38#include <stdlib.h>
39#include <wchar.h>
40#include "un-namespace.h"
41#include "libc_private.h"
42#include "local.h"
43#include "mblocal.h"
44#include "xlocale_private.h"
45
46/*
47 * MT-safe version.
48 */
49wint_t
50fgetwc_l(FILE *fp, locale_t locale)
51{
52	wint_t r;
53	FIX_LOCALE(locale);
54
55	FLOCKFILE(fp);
56	ORIENT(fp, 1);
57	r = __fgetwc(fp, locale);
58	FUNLOCKFILE(fp);
59
60	return (r);
61}
62
63wint_t
64fgetwc(FILE *fp)
65{
66	return fgetwc_l(fp, __get_locale());
67}
68
69/*
70 * Internal (non-MPSAFE) version of fgetwc().  This version takes an
71 * mbstate_t argument specifying the initial conversion state.  For
72 * wide streams, this should always be fp->_mbstate.  On return, *nread
73 * is set to the number of bytes read.
74 */
75wint_t
76__fgetwc_mbs(FILE *fp, mbstate_t *mbs, int *nread, locale_t locale)
77{
78	wchar_t wc;
79	size_t nconv;
80	struct xlocale_ctype *l = XLOCALE_CTYPE(locale);
81
82	if (fp->_r <= 0 && __srefill(fp)) {
83		*nread = 0;
84		return (WEOF);
85	}
86	if (MB_CUR_MAX == 1) {
87		/* Fast path for single-byte encodings. */
88		wc = *fp->_p++;
89		fp->_r--;
90		*nread = 1;
91		return (wc);
92	}
93	*nread = 0;
94	do {
95		nconv = l->__mbrtowc(&wc, fp->_p, fp->_r, mbs);
96		if (nconv == (size_t)-1)
97			break;
98		else if (nconv == (size_t)-2)
99			continue;
100		else if (nconv == 0) {
101			fp->_p++;
102			fp->_r--;
103			(*nread)++;
104			return (L'\0');
105		} else {
106			fp->_p += nconv;
107			fp->_r -= nconv;
108			*nread += nconv;
109			return (wc);
110		}
111	} while (__srefill(fp) == 0);
112	fp->_flags |= __SERR;
113	errno = EILSEQ;
114	return (WEOF);
115}
116