<sys/ipc.h>(0P)                                     POSIX Programmer's Manual                                    <sys/ipc.h>(0P)



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 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 Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6,  Copy-
       right (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.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                               <sys/ipc.h>(0P)