1 /* $OpenBSD: fgetwln.c,v 1.4 2016/08/27 12:08:38 schwarze 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 <stdio.h>
30 #include <stdlib.h>
31 #include <wchar.h>
32 #include "local.h"
33
34 /*
35 * Expand the line buffer. Return -1 on error.
36 */
37 static int
__slbexpand(FILE * fp,size_t newsize)38 __slbexpand(FILE *fp, size_t newsize)
39 {
40 void *p;
41
42 if (fp->_lb._size / sizeof(wchar_t) >= newsize)
43 return 0;
44 if ((p = reallocarray(fp->_lb._base, newsize, sizeof(wchar_t))) == NULL)
45 return -1;
46 fp->_lb._base = p;
47 fp->_lb._size = newsize * sizeof(wchar_t);
48 return 0;
49 }
50
51 wchar_t *
fgetwln(FILE * __restrict fp,size_t * lenp)52 fgetwln(FILE * __restrict fp, size_t *lenp)
53 {
54 wint_t wc;
55 size_t len;
56
57 FLOCKFILE(fp);
58 _SET_ORIENTATION(fp, 1);
59
60 len = 0;
61 while ((wc = __fgetwc_unlock(fp)) != WEOF) {
62 #define GROW 512
63 if (len >= fp->_lb._size / sizeof(wchar_t) &&
64 __slbexpand(fp, len + GROW)) {
65 fp->_flags |= __SERR;
66 goto error;
67 }
68 *((wchar_t *)fp->_lb._base + len++) = wc;
69 if (wc == L'\n')
70 break;
71 }
72
73 /*
74 * The following test assumes that fgetwc() fails when
75 * feof() is already set, and that fgetwc() will never
76 * set feof() in the same call where it also sets ferror()
77 * or returns non-WEOF.
78 * Testing ferror() would not be better because fgetwc()
79 * may succeed even when ferror() is already set.
80 */
81
82 if (len == 0 || (wc == WEOF && !__sfeof(fp)))
83 goto error;
84
85 FUNLOCKFILE(fp);
86 *lenp = len;
87 return (wchar_t *)fp->_lb._base;
88
89 error:
90 FUNLOCKFILE(fp);
91 *lenp = 0;
92 return NULL;
93 }
94