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      1 /* Copyright (C) 2000, 2009-2012 Free Software Foundation, Inc.
      2    This file is part of the GNU C Library.
      3 
      4    This program is free software: you can redistribute it and/or modify
      5    it under the terms of the GNU General Public License as published by
      6    the Free Software Foundation; either version 3 of the License, or
      7    (at your option) any later version.
      8 
      9    This program 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
     12    GNU General Public License for more details.
     13 
     14    You should have received a copy of the GNU General Public License
     15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
     16 
     17 #include <config.h>
     18 
     19 /* Specification.  */
     20 #include <spawn.h>
     21 
     22 #include <errno.h>
     23 #include <unistd.h>
     24 
     25 #if !_LIBC
     26 # define __sysconf(open_max) getdtablesize ()
     27 #endif
     28 
     29 #if !HAVE_WORKING_POSIX_SPAWN
     30 # include "spawn_int.h"
     31 #endif
     32 
     33 /* Add an action to FILE-ACTIONS which tells the implementation to call
     34    'dup2' for the given file descriptors during the 'spawn' call.  */
     35 int
     36 posix_spawn_file_actions_adddup2 (posix_spawn_file_actions_t *file_actions,
     37                                   int fd, int newfd)
     38 #undef posix_spawn_file_actions_adddup2
     39 {
     40   int maxfd = __sysconf (_SC_OPEN_MAX);
     41 
     42   /* Test for the validity of the file descriptor.  */
     43   if (fd < 0 || newfd < 0 || fd >= maxfd || newfd >= maxfd)
     44     return EBADF;
     45 
     46 #if HAVE_WORKING_POSIX_SPAWN
     47   return posix_spawn_file_actions_adddup2 (file_actions, fd, newfd);
     48 #else
     49   /* Allocate more memory if needed.  */
     50   if (file_actions->_used == file_actions->_allocated
     51       && __posix_spawn_file_actions_realloc (file_actions) != 0)
     52     /* This can only mean we ran out of memory.  */
     53     return ENOMEM;
     54 
     55   {
     56     struct __spawn_action *rec;
     57 
     58     /* Add the new value.  */
     59     rec = &file_actions->_actions[file_actions->_used];
     60     rec->tag = spawn_do_dup2;
     61     rec->action.dup2_action.fd = fd;
     62     rec->action.dup2_action.newfd = newfd;
     63 
     64     /* Account for the new entry.  */
     65     ++file_actions->_used;
     66 
     67     return 0;
     68   }
     69 #endif
     70 }
     71