1 /* Copyright (C) 1995-2021 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 <https://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 #ifdef __USE_GNU 34 # define IPC_INFO 3 /* See ipcs. */ 35 #endif 36 37 /* Special key values. */ 38 #define IPC_PRIVATE ((__key_t) 0) /* Private key. */ 39 40 41 /* Data structure used to pass permission information to IPC operations. */ 42 struct ipc_perm 43 { 44 __key_t __key; /* Key. */ 45 unsigned short int uid; /* Owner's user ID. */ 46 unsigned short int gid; /* Owner's group ID. */ 47 unsigned short int cuid; /* Creator's user ID. */ 48 unsigned short int cgid; /* Creator's group ID. */ 49 unsigned short int mode; /* Read/write permission. */ 50 unsigned short int __seq; /* Sequence number. */ 51 }; 52