posix/spawn_faction_addopen.c

   1 /* Copyright (C) 2000-2015 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 #include <stdlib.h>
  22 #include <string.h>
  23
  24 #include "spawn_int.h"
  25
  26 /* Add an action to FILE-ACTIONS which tells the implementation to call
  27    `open' for the given file during the `spawn' call.  */
  28 int
  29 posix_spawn_file_actions_addopen (posix_spawn_file_actions_t *file_actions,
  30                                   int fd, const char *path, int oflag,
  31                                   mode_t mode)
  32 {
  33   int maxfd = __sysconf (_SC_OPEN_MAX);
  34   struct __spawn_action *rec;
  35
  36   /* Test for the validity of the file descriptor.  */
  37   if (fd < 0 || fd >= maxfd)
  38     return EBADF;
  39
  40   char *path_copy = strdup (path);
  41   if (path_copy == NULL)
  42     return ENOMEM;
  43
  44   /* Allocate more memory if needed.  */
  45   if (file_actions->__used == file_actions->__allocated
  46       && __posix_spawn_file_actions_realloc (file_actions) != 0)
  47     {
  48       /* This can only mean we ran out of memory.  */
  49       free (path_copy);
  50       return ENOMEM;
  51     }
  52
  53   /* Add the new value.  */
  54   rec = &file_actions->__actions[file_actions->__used];
  55   rec->tag = spawn_do_open;
  56   rec->action.open_action.fd = fd;
  57   rec->action.open_action.path = path_copy;
  58   rec->action.open_action.oflag = oflag;
  59   rec->action.open_action.mode = mode;
  60
  61   /* Account for the new entry.  */
  62   ++file_actions->__used;
  63
  64   return 0;
  65 }