0p:ipc.h
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sys/ipc.h - XSI interprocess communication access structure
#include <sys/ipc.h>
Contents |
DESCRIPTION
The <sys/ipc.h> header is used by three mechanisms for XSI interprocess communication (IPC): messages,
semaphores, and shared memory. All use a common structure type, ipc_perm, to pass information used in determining
permission to perform an IPC operation.
The ipc_perm structure shall contain the following members:
uid_t uid Owner's user ID.
gid_t gid Owner's group ID.
uid_t cuid Creator's user ID.
gid_t cgid Creator's group ID.
mode_t mode Read/write permission.
The uid_t, gid_t, mode_t, and key_t types shall be defined as described in <sys/types.h> .
Definitions shall be provided for the following constants:
Mode bits:
IPC_CREAT
Create entry if key does not exist.
IPC_EXCL
Fail if key exists.
IPC_NOWAIT
Error if request must wait.
Keys:
IPC_PRIVATE
Private key.
Control commands:
IPC_RMID
Remove identifier.
IPC_SET
Set options.
IPC_STAT
Get options.
The following shall be declared as a function and may also be defined as a macro. A function prototype shall be
provided.
key_t ftok(const char *, int);
The following sections are informative.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
RELATED
<sys/types.h> , the System Interfaces volume of IEEE Std 1003.1-2001, ftok()
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Stan-
dard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifica-
tions Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open
Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard,
the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained
online at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 <sys/ipc.h>(P)