ipc.h

<sys/ipc.h>(P)						       <sys/ipc.h>(P)



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 interpro-
       cess 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.

SEE ALSO
       <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, Standard for Information  Technol-
       ogy  --	Portable  Operating  System Interface (POSIX), The Open Group
       Base Specifications 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 .



POSIX				     2003		       <sys/ipc.h>(P)