io/closefrom.c

   1 /* Close a range of file descriptors.
   2    Copyright (C) 2021-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <stdbool.h>
  20 #include <stdio.h>
  21 #include <sys/param.h>
  22 #include <unistd.h>
  23
  24 void
  25 __closefrom (int lowfd)
  26 {
  27   int l = MAX (0, lowfd);
  28
  29   int r = __close_range (l, ~0U, 0);
  30   if (r == 0)
  31     return ;
  32
  33   if (!__closefrom_fallback (l, true))
  34     __fortify_fail ("closefrom failed to close a file descriptor");
  35 }
  36 weak_alias (__closefrom, closefrom)