sys_ipc.h(0P)		   POSIX Programmer's Manual		 sys_ipc.h(0P)

PROLOG
       This manual page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the corresponding
       Linux manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.

NAME
       sys/ipc.h — XSI interprocess communication access structure

SYNOPSIS
       #include <sys/ipc.h>

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 <sys/ipc.h> header shall define the ipc_perm structure, which shall
       include 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 <sys/ipc.h> header shall define the uid_t, gid_t, mode_t, and key_t
       types as described in <sys/types.h>.

       The <sys/ipc.h> header shall define the following symbolic 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.

SEE ALSO
       <sys_types.h>

       The System Interfaces volume of POSIX.1‐2017, ftok()

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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 .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group		     2017			 sys_ipc.h(0P)