xref: /freebsd/lib/libc/stdio/fgetws.c (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
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("$FreeBSD$");
34 
35 #include "namespace.h"
36 #include <errno.h>
37 #include <stdio.h>
38 #include <string.h>
39 #include <wchar.h>
40 #include "un-namespace.h"
41 #include "libc_private.h"
42 #include "local.h"
43 #include "mblocal.h"
44 
45 wchar_t *
46 fgetws_l(wchar_t * __restrict ws, int n, FILE * __restrict fp, locale_t locale)
47 {
48 	wchar_t *wsp;
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(fp);
56 	ORIENT(fp, 1);
57 
58 	if (n <= 0) {
59 		errno = EINVAL;
60 		goto error;
61 	}
62 
63 	if (fp->_r <= 0 && __srefill(fp))
64 		/* EOF */
65 		goto error;
66 	wsp = ws;
67 	do {
68 		src = fp->_p;
69 		nl = memchr(fp->_p, '\n', fp->_r);
70 		nconv = l->__mbsnrtowcs(wsp, &src,
71 		    nl != NULL ? (nl - fp->_p + 1) : fp->_r,
72 		    n - 1, &fp->_mbstate);
73 		if (nconv == (size_t)-1)
74 			/* Conversion error */
75 			goto error;
76 		if (src == NULL) {
77 			/*
78 			 * We hit a null byte. Increment the character count,
79 			 * since mbsnrtowcs()'s return value doesn't include
80 			 * the terminating null, then resume conversion
81 			 * after the null.
82 			 */
83 			nconv++;
84 			src = memchr(fp->_p, '\0', fp->_r);
85 			src++;
86 		}
87 		fp->_r -= (unsigned char *)src - fp->_p;
88 		fp->_p = (unsigned char *)src;
89 		n -= nconv;
90 		wsp += nconv;
91 	} while (wsp[-1] != L'\n' && n > 1 && (fp->_r > 0 ||
92 	    __srefill(fp) == 0));
93 	if (wsp == ws)
94 		/* EOF */
95 		goto error;
96 	if (!l->__mbsinit(&fp->_mbstate))
97 		/* Incomplete character */
98 		goto error;
99 	*wsp = L'\0';
100 	FUNLOCKFILE(fp);
101 
102 	return (ws);
103 
104 error:
105 	FUNLOCKFILE(fp);
106 	return (NULL);
107 }
108 wchar_t *
109 fgetws(wchar_t * __restrict ws, int n, FILE * __restrict fp)
110 {
111 	return fgetws_l(ws, n, fp, __get_locale());
112 }
113