struct ipc_perm {
key_t __ipc_perm_key;
uid_t uid;
gid_t gid;
uid_t cuid;
gid_t cgid;
mode_t mode;
unsigned short __pad1;
unsigned short __ipc_perm_seq;
unsigned long __pad2;
unsigned long __pad3;
};
#define IPC_64 0x100