librt/spawn_faction_addclose.c

   1 /* Copyright (C) 2000 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    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <spawn.h>
  20 #include <unistd.h>
  21
  22 #include "spawn_int.h"
  23
  24 /* Add an action to FILE-ACTIONS which tells the implementation to call
  25    `close' for the given file descriptor during the `spawn' call.  */
  26 int
  27 posix_spawn_file_actions_addclose(posix_spawn_file_actions_t *file_actions,
  28                                   int fd)
  29 {
  30         int maxfd = sysconf(_SC_OPEN_MAX);
  31         struct __spawn_action *rec;
  32
  33         /* Test for the validity of the file descriptor.  */
  34         if (fd < 0 || fd >= maxfd)
  35                 return EBADF;
  36
  37         /* Allocate more memory if needed.  */
  38         if (file_actions->__used == file_actions->__allocated
  39             && __posix_spawn_file_actions_realloc(file_actions) != 0)
  40                 /* This can only mean we ran out of memory.  */
  41                 return ENOMEM;
  42
  43         /* Add the new value.  */
  44         rec = &file_actions->__actions[file_actions->__used];
  45         rec->tag = spawn_do_close;
  46         rec->action.open_action.fd = fd;
  47
  48         /* Account for the new entry.  */
  49         ++file_actions->__used;
  50         return 0;
  51 }