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 <errno.h>
      20  #include <not-cancel.h>
      21  #include <unistd.h>
      22  
      23  /* Close the file descriptors from FIRST up to LAST, inclusive.  */
      24  int
      25  __close_range (unsigned int first, unsigned int last,
      26  	       int flags)
      27  {
      28    if (first > last || flags != 0)
      29      {
      30        __set_errno (EINVAL);
      31        return -1;
      32      }
      33  
      34    int maxfd = __getdtablesize ();
      35    if (maxfd == -1)
      36      return -1;
      37  
      38    for (int i = first; i <= last && i < maxfd; i++)
      39      __close_nocancel_nostatus (i);
      40  
      41    return 0;
      42  }
      43  libc_hidden_def (__close_range)
      44  weak_alias (__close_range, close_range)