1  /* Copyright (C) 1991-2023 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 <limits.h>
      19  #include <unistd.h>
      20  #include <sys/resource.h>
      21  
      22  /* Return the maximum number of file descriptors
      23     the current process could possibly have.  */
      24  int
      25  __getdtablesize (void)
      26  {
      27    struct rlimit ru;
      28  
      29    /* This should even work if `getrlimit' is not implemented.  POSIX.1
      30       does not define this function but we will generate a stub which
      31       returns -1.  */
      32    return __getrlimit (RLIMIT_NOFILE, &ru) < 0 ? OPEN_MAX : ru.rlim_cur;
      33  }
      34  
      35  weak_alias (__getdtablesize, getdtablesize)