xref: /freebsd/lib/libc/stdio/fgetws.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2002-2004 Tim J. Robbins.
5  * All rights reserved.
6  *
7  * Copyright (c) 2011 The FreeBSD Foundation
8  *
9  * Portions of this software were developed by David Chisnall
10  * under sponsorship from the FreeBSD Foundation.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include "namespace.h"
35 #include <errno.h>
36 #include <stdio.h>
37 #include <string.h>
38 #include <wchar.h>
39 #include "un-namespace.h"
40 #include "libc_private.h"
41 #include "local.h"
42 #include "mblocal.h"
43 
44 wchar_t *
45 fgetws_l(wchar_t * __restrict ws, int n, FILE * __restrict fp, locale_t locale)
46 {
47 	int sret;
48 	wchar_t *wsp, *ret;
49 	size_t nconv;
50 	const char *src;
51 	unsigned char *nl;
52 	FIX_LOCALE(locale);
53 	struct xlocale_ctype *l = XLOCALE_CTYPE(locale);
54 
55 	FLOCKFILE_CANCELSAFE(fp);
56 	ORIENT(fp, 1);
57 
58 	if (n <= 0) {
59 		fp->_flags |= __SERR;
60 		errno = EINVAL;
61 		goto error;
62 	}
63 
64 	wsp = ws;
65 	if (n == 1)
66 		goto ok;
67 
68 	if (fp->_r <= 0 && __srefill(fp))
69 		/* EOF or ferror */
70 		goto error;
71 
72 	sret = 0;
73 	do {
74 		src = fp->_p;
75 		nl = memchr(fp->_p, '\n', fp->_r);
76 		nconv = l->__mbsnrtowcs(wsp, &src,
77 		    nl != NULL ? (nl - fp->_p + 1) : fp->_r,
78 		    n - 1, &fp->_mbstate);
79 		if (nconv == (size_t)-1) {
80 			/* Conversion error */
81 			fp->_flags |= __SERR;
82 			goto error;
83 		}
84 		if (src == NULL) {
85 			/*
86 			 * We hit a null byte. Increment the character count,
87 			 * since mbsnrtowcs()'s return value doesn't include
88 			 * the terminating null, then resume conversion
89 			 * after the null.
90 			 */
91 			nconv++;
92 			src = memchr(fp->_p, '\0', fp->_r);
93 			src++;
94 		}
95 		fp->_r -= (unsigned char *)src - fp->_p;
96 		fp->_p = (unsigned char *)src;
97 		n -= nconv;
98 		wsp += nconv;
99 	} while ((wsp == ws || wsp[-1] != L'\n') && n > 1 && (fp->_r > 0 ||
100 	    (sret = __srefill(fp)) == 0));
101 	if (sret && !__sfeof(fp))
102 		/* ferror */
103 		goto error;
104 	if (!l->__mbsinit(&fp->_mbstate)) {
105 		/* Incomplete character */
106 		fp->_flags |= __SERR;
107 		errno = EILSEQ;
108 		goto error;
109 	}
110 	if (wsp == ws)
111 		/* EOF */
112 		goto error;
113 ok:
114 	*wsp = L'\0';
115 	ret = ws;
116 end:
117 	FUNLOCKFILE_CANCELSAFE();
118 	return (ret);
119 
120 error:
121 	ret = NULL;
122 	goto end;
123 }
124 
125 wchar_t *
126 fgetws(wchar_t * __restrict ws, int n, FILE * __restrict fp)
127 {
128 	return fgetws_l(ws, n, fp, __get_locale());
129 }
130