1 /*-
2 * Copyright (c) 2002-2004 Tim J. Robbins.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 /*
28 FUNCTION
29 <<fgetwc>>, <<getwc>>, <<fgetwc_unlocked>>, <<getwc_unlocked>>---get a wide character from a file or stream
30
31 INDEX
32 fgetwc
33 INDEX
34 fgetwc_unlocked
35 INDEX
36 _fgetwc_r
37 INDEX
38 _fgetwc_unlocked_r
39 INDEX
40 getwc
41 INDEX
42 getwc_unlocked
43 INDEX
44 _getwc_r
45 INDEX
46 _getwc_unlocked_r
47
48 SYNOPSIS
49 #include <stdio.h>
50 #include <wchar.h>
51 wint_t fgetwc(FILE *<[fp]>);
52
53 #define _GNU_SOURCE
54 #include <stdio.h>
55 #include <wchar.h>
56 wint_t fgetwc_unlocked(FILE *<[fp]>);
57
58 #include <stdio.h>
59 #include <wchar.h>
60 wint_t fgetwc( FILE *<[fp]>);
61
62 #include <stdio.h>
63 #include <wchar.h>
64 wint_t fgetwc_unlocked( FILE *<[fp]>);
65
66 #include <stdio.h>
67 #include <wchar.h>
68 wint_t getwc(FILE *<[fp]>);
69
70 #define _GNU_SOURCE
71 #include <stdio.h>
72 #include <wchar.h>
73 wint_t getwc_unlocked(FILE *<[fp]>);
74
75 #include <stdio.h>
76 #include <wchar.h>
77 wint_t getwc( FILE *<[fp]>);
78
79 #include <stdio.h>
80 #include <wchar.h>
81 wint_t getwc_unlocked( FILE *<[fp]>);
82
83 DESCRIPTION
84 Use <<fgetwc>> to get the next wide character from the file or stream
85 identified by <[fp]>. As a side effect, <<fgetwc>> advances the file's
86 current position indicator.
87
88 <<fgetwc_unlocked>> is a non-thread-safe version of <<fgetwc>>.
89 <<fgetwc_unlocked>> may only safely be used within a scope
90 protected by flockfile() (or ftrylockfile()) and funlockfile(). This
91 function may safely be used in a multi-threaded program if and only
92 if they are called while the invoking thread owns the (FILE *)
93 object, as is the case after a successful call to the flockfile() or
94 ftrylockfile() functions. If threads are disabled, then
95 <<fgetwc_unlocked>> is equivalent to <<fgetwc>>.
96
97 The <<getwc>> and <<getwc_unlocked>> functions or macros functions identically
98 to <<fgetwc>> and <<fgetwc_unlocked>>. It may be implemented as a macro, and
99 may evaluate its argument more than once. There is no reason ever to use it.
100
101 <<_fgetwc_r>>, <<_getwc_r>>, <<_fgetwc_unlocked_r>>, and <<_getwc_unlocked_r>>
102 are simply reentrant versions of the above functions that are passed the
103 additional reentrant structure pointer argument: <[ptr]>.
104
105 RETURNS
106 The next wide character cast to <<wint_t>>, unless there is no more data,
107 or the host system reports a read error; in either of these situations,
108 <<fgetwc>> and <<getwc>> return <<WEOF>>.
109
110 You can distinguish the two situations that cause an <<EOF>> result by
111 using the <<ferror>> and <<feof>> functions.
112
113 PORTABILITY
114 <<fgetwc>> and <<getwc>> are required by C99 and POSIX.1-2001.
115
116 <<fgetwc_unlocked>> and <<getwc_unlocked>> are GNU extensions.
117 */
118
119 #define _DEFAULT_SOURCE
120 #include <_ansi.h>
121 #include <errno.h>
122 #include <stdio.h>
123 #include <stdlib.h>
124 #include <wchar.h>
125 #include "local.h"
126
127 wint_t
__fgetwc(register FILE * fp)128 __fgetwc (
129 register FILE *fp)
130 {
131 wchar_t wc;
132 size_t nconv;
133
134 if (fp->_r <= 0 && _srefill ( fp))
135 return (WEOF);
136 if (MB_CUR_MAX == 1)
137 {
138 /* Fast path for single-byte encodings. */
139 wc = *fp->_p++;
140 fp->_r--;
141 return (wc);
142 }
143 do
144 {
145 nconv = mbrtowc (&wc, (char *) fp->_p, fp->_r, &fp->_mbstate);
146 if (nconv == (size_t)-1)
147 break;
148 else if (nconv == (size_t)-2)
149 continue;
150 else if (nconv == 0)
151 {
152 /*
153 * Assume that the only valid representation of
154 * the null wide character is a single null byte.
155 */
156 fp->_p++;
157 fp->_r--;
158 return (L'\0');
159 }
160 else
161 {
162 fp->_p += nconv;
163 fp->_r -= nconv;
164 return (wc);
165 }
166 }
167 while (_srefill( fp) == 0);
168 fp->_flags |= __SERR;
169 errno = EILSEQ;
170 return (WEOF);
171 }
172
173 wint_t
fgetwc(register FILE * fp)174 fgetwc (
175 register FILE *fp)
176 {
177 wint_t r;
178
179 _newlib_flockfile_start (fp);
180 if (ORIENT(fp, 1) != 1)
181 r = WEOF;
182 else
183 r = __fgetwc (fp);
184 _newlib_flockfile_end (fp);
185 return r;
186 }
187
