bits/ipc.h

   1 /* Copyright (C) 1995-2018 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 #ifndef _SYS_IPC_H
  19 # error "Never use <bits/ipc.h> directly; include <sys/ipc.h> instead."
  20 #endif
  21
  22 #include <bits/types.h>
  23
  24 /* Mode bits for `msgget', `semget', and `shmget'.  */
  25 #define IPC_CREAT       01000           /* create key if key does not exist */
  26 #define IPC_EXCL        02000           /* fail if key exists */
  27 #define IPC_NOWAIT      04000           /* return error on wait */
  28
  29 /* Control commands for `msgctl', `semctl', and `shmctl'.  */
  30 #define IPC_RMID        0               /* remove identifier */
  31 #define IPC_SET         1               /* set `ipc_perm' options */
  32 #define IPC_STAT        2               /* get `ipc_perm' options */
  33
  34 /* Special key values.  */
  35 #define IPC_PRIVATE     ((key_t) 0)     /* private key */
  36
  37
  38 /* Data structure used to pass permission information to IPC operations.  */
  39 struct ipc_perm
  40   {
  41     __uid_t uid;                        /* owner's user ID */
  42     __gid_t gid;                        /* owner's group ID */
  43     __uid_t cuid;                       /* creator's user ID */
  44     __gid_t cgid;                       /* creator's group ID */
  45     __mode_t mode;                      /* read/write permission */
  46   };