xref: /freebsd/lib/libc/stdio/fgetws.c (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
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 <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include "namespace.h"
38 #include <errno.h>
39 #include <stdio.h>
40 #include <string.h>
41 #include <wchar.h>
42 #include "un-namespace.h"
43 #include "libc_private.h"
44 #include "local.h"
45 #include "mblocal.h"
46 
47 wchar_t *
48 fgetws_l(wchar_t * __restrict ws, int n, FILE * __restrict fp, locale_t locale)
49 {
50 	int sret;
51 	wchar_t *wsp, *ret;
52 	size_t nconv;
53 	const char *src;
54 	unsigned char *nl;
55 	FIX_LOCALE(locale);
56 	struct xlocale_ctype *l = XLOCALE_CTYPE(locale);
57 
58 	FLOCKFILE_CANCELSAFE(fp);
59 	ORIENT(fp, 1);
60 
61 	if (n <= 0) {
62 		fp->_flags |= __SERR;
63 		errno = EINVAL;
64 		goto error;
65 	}
66 
67 	wsp = ws;
68 	if (n == 1)
69 		goto ok;
70 
71 	if (fp->_r <= 0 && __srefill(fp))
72 		/* EOF or ferror */
73 		goto error;
74 
75 	sret = 0;
76 	do {
77 		src = fp->_p;
78 		nl = memchr(fp->_p, '\n', fp->_r);
79 		nconv = l->__mbsnrtowcs(wsp, &src,
80 		    nl != NULL ? (nl - fp->_p + 1) : fp->_r,
81 		    n - 1, &fp->_mbstate);
82 		if (nconv == (size_t)-1) {
83 			/* Conversion error */
84 			fp->_flags |= __SERR;
85 			goto error;
86 		}
87 		if (src == NULL) {
88 			/*
89 			 * We hit a null byte. Increment the character count,
90 			 * since mbsnrtowcs()'s return value doesn't include
91 			 * the terminating null, then resume conversion
92 			 * after the null.
93 			 */
94 			nconv++;
95 			src = memchr(fp->_p, '\0', fp->_r);
96 			src++;
97 		}
98 		fp->_r -= (unsigned char *)src - fp->_p;
99 		fp->_p = (unsigned char *)src;
100 		n -= nconv;
101 		wsp += nconv;
102 	} while ((wsp == ws || wsp[-1] != L'\n') && n > 1 && (fp->_r > 0 ||
103 	    (sret = __srefill(fp)) == 0));
104 	if (sret && !__sfeof(fp))
105 		/* ferror */
106 		goto error;
107 	if (!l->__mbsinit(&fp->_mbstate)) {
108 		/* Incomplete character */
109 		fp->_flags |= __SERR;
110 		errno = EILSEQ;
111 		goto error;
112 	}
113 	if (wsp == ws)
114 		/* EOF */
115 		goto error;
116 ok:
117 	*wsp = L'\0';
118 	ret = ws;
119 end:
120 	FUNLOCKFILE_CANCELSAFE();
121 	return (ret);
122 
123 error:
124 	ret = NULL;
125 	goto end;
126 }
127 
128 wchar_t *
129 fgetws(wchar_t * __restrict ws, int n, FILE * __restrict fp)
130 {
131 	return fgetws_l(ws, n, fp, __get_locale());
132 }
133