lib/spawn_faction_addopen.c

   1 /* Copyright (C) 2000, 2009-2017 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    'open' for the given file during the 'spawn' call.  */
  35 int
  36 posix_spawn_file_actions_addopen (posix_spawn_file_actions_t *file_actions,
  37                                   int fd, const char *path, int oflag,
  38                                   mode_t mode)
  39 #undef posix_spawn_file_actions_addopen
  40 {
  41   int maxfd = __sysconf (_SC_OPEN_MAX);
  42
  43   /* Test for the validity of the file descriptor.  */
  44   if (fd < 0 || fd >= maxfd)
  45     return EBADF;
  46
  47 #if HAVE_WORKING_POSIX_SPAWN
  48   return posix_spawn_file_actions_addopen (file_actions, fd, path, oflag, mode);
  49 #else
  50   /* Allocate more memory if needed.  */
  51   if (file_actions->_used == file_actions->_allocated
  52       && __posix_spawn_file_actions_realloc (file_actions) != 0)
  53     /* This can only mean we ran out of memory.  */
  54     return ENOMEM;
  55
  56   {
  57     struct __spawn_action *rec;
  58
  59     /* Add the new value.  */
  60     rec = &file_actions->_actions[file_actions->_used];
  61     rec->tag = spawn_do_open;
  62     rec->action.open_action.fd = fd;
  63     rec->action.open_action.path = path;
  64     rec->action.open_action.oflag = oflag;
  65     rec->action.open_action.mode = mode;
  66
  67     /* Account for the new entry.  */
  68     ++file_actions->_used;
  69
  70     return 0;
  71   }
  72 #endif
  73 }