msgsys(2)                        DG/UX 5.4.2                       msgsys(2)


NAME
       msgsys - perform a message queue operation

SYNOPSIS
       #include <sys/types.h>
       #include <sys/ipc.h>
       #include <sys/msg.h>

       int   msgsys (P1, P2, P3, P4, P5, P6)
       int   P1;
       int   P2;
       int   P3;
       int   P4;
       int   P5;
       int   P6;

   where:
       P1     An argument indicating the type of operation to be performed
              with message queues (0 = MSGGET, 1 = MSGCTL, 2 = MSGRCV, 3 =
              MSGSND).

       P2     If the operation is MSGGET, P2 is equal to the message queue
              key.  Otherwise, P2 is equal to the message queue id.

       P3     If the operation is MSGGET, P3 equals the flags that indicate
              whether to create the queue or not and the permissions for the
              queue.  If the operation is MSGCTL, P3 equals the control
              command number which specifies the type of control command to
              perform.  If the operation is MSGSND or MSGRCV, P3 equals the
              pointer to the message to be sent or received.

       P4     If the operation is MSGGET, P4 is invalid.  In case of MSGCTL,
              P4 is a pointer to a buffer containing information about the
              message queue.  In case of MSGSND and MSGRCV, P4 is equal to
              the size of the message's text portion.

       P5     If the operation is MSGGET or MSGCTL, P5 is invalid.  In case
              of MSGRCV P5 is equal to the message type.  In case of MSGSND
              P5 is equal to the message flags modifying the message MSGSND
              operation.

       P6     If the operation is MSGRCV, P6 is equal to the message flags
              modifying the MSGRCV operation.  Otherwise P6 is invalid.

DESCRIPTION
       Msgsys(2) performs a message operation (MSGGET, MSGCTL, MSGSND,
       MSGRCV) indicated by the value of P1.

ACCESS CONTROL
       See the description of the exception condition EACCES below.







Licensed material--property of copyright holder(s)                         1

msgsys(2)                        DG/UX 5.4.2                       msgsys(2)


RETURN VALUE
       msqid     A non-negative integer that identifies the message queue
                 associated with key, returned by msgget.

       0         Msgsnd, msgrcv or msgctl calls were successful.

       -1        An error occurred.  errno is set to indicate the error.

DIAGNOSTICS
       The error codes returned depend on the type of message queue
       operations performed and are described in msgget(2), msgctl(2),
       msgsnd(2), msgrcv(2).

       EINVAL    P1 argument is not in the range of 0 through 3.

SEE ALSO
       intro(2), msgctl(2), msgget(2), msgrcv(2), msgsnd(2).








































Licensed material--property of copyright holder(s)                         2