1 /* $NetBSD: fgetwln.c,v 1.8 2016/08/27 13:15:48 christos Exp $ */
2
3 /*-
4 * Copyright (c) 2002-2004 Tim J. Robbins.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 #if defined(LIBC_SCCS) && !defined(lint)
31 #if 0
32 __FBSDID("$FreeBSD: src/lib/libc/stdio/fgetwln.c,v 1.2 2004/08/06 17:00:09 tjr Exp $");
33 #else
34 __RCSID("$NetBSD: fgetwln.c,v 1.8 2016/08/27 13:15:48 christos Exp $");
35 #endif
36 #endif /* LIBC_SCCS and not lint */
37
38 #include "namespace.h"
39 #include <assert.h>
40 #include <errno.h>
41 #include <limits.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <wchar.h>
45 #include "reentrant.h"
46 #include "local.h"
47
48 #ifdef __weak_alias
__weak_alias(fgetwln,_fgetwln)49 __weak_alias(fgetwln,_fgetwln)
50 #endif
51
52 /*
53 * Expand the line buffer. Return -1 on error.
54 #ifdef notdef
55 * The `new size' does not account for a terminating '\0',
56 * so we add 1 here.
57 #endif
58 */
59 static int
60 __slbexpand(FILE *fp, size_t newsize)
61 {
62 void *p;
63
64 #ifdef notdef
65 ++newsize;
66 #endif
67 _DIAGASSERT(fp != NULL);
68
69 if (_EXT(fp)->_fgetstr_len >= newsize)
70 return 0;
71 if ((p = realloc(_EXT(fp)->_fgetstr_buf, newsize)) == NULL)
72 return -1;
73 _EXT(fp)->_fgetstr_buf = p;
74 _EXT(fp)->_fgetstr_len = newsize;
75 return 0;
76 }
77
78 wchar_t *
fgetwln(FILE * __restrict fp,size_t * lenp)79 fgetwln(FILE * __restrict fp, size_t *lenp)
80 {
81 wint_t wc;
82 size_t len;
83
84 FLOCKFILE(fp);
85 _SET_ORIENTATION(fp, 1);
86
87 len = 0;
88 while ((wc = __fgetwc_unlock(fp)) != WEOF) {
89 #define GROW 512
90 if (len * sizeof(wchar_t) >= _EXT(fp)->_fgetstr_len &&
91 __slbexpand(fp, (len + GROW) * sizeof(wchar_t))) {
92 fp->_flags |= __SERR;
93 goto error;
94 }
95 *((wchar_t *)(void *)_EXT(fp)->_fgetstr_buf + len++) = wc;
96 if (wc == L'\n')
97 break;
98 }
99
100 /*
101 * The following test assumes that fgetwc() fails when
102 * feof() is already set, and that fgetwc() will never
103 * set feof() in the same call where it also sets ferror()
104 * or returns non-WEOF.
105 * Testing ferror() would not be better because fgetwc()
106 * may succeed even when ferror() is already set.
107 */
108
109 if (len == 0 || (wc == WEOF && !__sfeof(fp)))
110 goto error;
111
112 FUNLOCKFILE(fp);
113 *lenp = len;
114 return (wchar_t *)(void *)_EXT(fp)->_fgetstr_buf;
115
116 error:
117 FUNLOCKFILE(fp);
118 *lenp = 0;
119 return NULL;
120 }
121