1  /* Duplicate a file descriptor result, avoiding clobbering
       2     STD{IN,OUT,ERR}_FILENO, with specific flags.
       3  
       4     Copyright (C) 2001, 2004-2006, 2009-2023 Free Software Foundation, Inc.
       5  
       6     This program is free software: you can redistribute it and/or modify
       7     it under the terms of the GNU General Public License as published by
       8     the Free Software Foundation, either version 3 of the License, or
       9     (at your option) any later version.
      10  
      11     This program is distributed in the hope that it will be useful,
      12     but WITHOUT ANY WARRANTY; without even the implied warranty of
      13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      14     GNU General Public License for more details.
      15  
      16     You should have received a copy of the GNU General Public License
      17     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      18  
      19  /* Written by Paul Eggert and Eric Blake.  */
      20  
      21  #include <config.h>
      22  
      23  /* Specification.  */
      24  #include "unistd-safer.h"
      25  
      26  #include <fcntl.h>
      27  #include <unistd.h>
      28  
      29  /* Like dup, but do not return STDIN_FILENO, STDOUT_FILENO, or
      30     STDERR_FILENO.  If FLAG contains O_CLOEXEC, behave like
      31     fcntl(F_DUPFD_CLOEXEC) rather than fcntl(F_DUPFD).  */
      32  
      33  int
      34  dup_safer_flag (int fd, int flag)
      35  {
      36    return fcntl (fd, (flag & O_CLOEXEC) ? F_DUPFD_CLOEXEC : F_DUPFD,
      37                  STDERR_FILENO + 1);
      38  }