summary refs log tree commit diff
path: root/debug/fgetws_chk.c
blob: fe934556ee18617bef294f362eadc57d1a2b0cdb (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
/* Copyright (C) 1993-2019 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include "libioP.h"
#include <wchar.h>
#include <sys/param.h>

wchar_t *
__fgetws_chk (wchar_t *buf, size_t size, int n, FILE *fp)
{
  size_t count;
  wchar_t *result;
  int old_error;
  CHECK_FILE (fp, NULL);
  if (n <= 0)
    return NULL;
  _IO_acquire_lock (fp);
  /* This is very tricky since a file descriptor may be in the
     non-blocking mode. The error flag doesn't mean much in this
     case. We return an error only when there is a new error. */
  old_error = fp->_flags & _IO_ERR_SEEN;
  fp->_flags &= ~_IO_ERR_SEEN;
  count = _IO_getwline (fp, buf, MIN ((size_t) n - 1, size), L'\n', 1);
  /* If we read in some bytes and errno is EAGAIN, that error will
     be reported for next read. */
  if (count == 0 || (_IO_ferror_unlocked (fp) && errno != EAGAIN))
    result = NULL;
  else if (count >= size)
    __chk_fail ();
  else
    {
      buf[count] = '\0';
      result = buf;
    }
  fp->_flags |= old_error;
  _IO_release_lock (fp);
  return result;
}