1/* Copyright (C) 1993-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include "libioP.h"
19#include <wchar.h>
20#include <sys/param.h>
21
22wchar_t *
23__fgetws_chk (wchar_t *buf, size_t size, int n, FILE *fp)
24{
25 size_t count;
26 wchar_t *result;
27 int old_error;
28 CHECK_FILE (fp, NULL);
29 if (n <= 0)
30 return NULL;
31 _IO_acquire_lock (fp);
32 /* This is very tricky since a file descriptor may be in the
33 non-blocking mode. The error flag doesn't mean much in this
34 case. We return an error only when there is a new error. */
35 old_error = fp->_flags & _IO_ERR_SEEN;
36 fp->_flags &= ~_IO_ERR_SEEN;
37 count = _IO_getwline (fp, buf, MIN ((size_t) n - 1, size), L'\n', 1);
38 /* If we read in some bytes and errno is EAGAIN, that error will
39 be reported for next read. */
40 if (count == 0 || (_IO_ferror_unlocked (fp) && errno != EAGAIN))
41 result = NULL;
42 else if (count >= size)
43 __chk_fail ();
44 else
45 {
46 buf[count] = '\0';
47 result = buf;
48 }
49 fp->_flags |= old_error;
50 _IO_release_lock (fp);
51 return result;
52}
53