1  /* Close a range of file descriptors.
       2     Copyright (C) 2021-2023 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)