Q: I use the SNDUSRMSG CL command in my batch programs in order to get input from the system operator. Is there a way that I can do the same thing in ILE RPG with APIs?

A: The Send User Message (SNDUSRMSG) CL command is actually a short cut for the Send Program Message (SNDPGMMSG) command followed by the Receive Message (RCVMSG) command.

To do the same thing as SNDUSRMSG with APIs requires you to use two steps. First, send a message to a non-program queue. Second, receive the reply message.

The QSYSOPR message queue is not a program queue. Confusingly, the SNDPGMMSG CL command can messages to non-program queues like QSYSOPR, but the Send Program Message (QMHSNDPM) API can't. To send messages to non-program message queues such as QSYSOPR, users' messages queues, or workstation message queues, you have to use the Send Non-program Message (QMHSNDM) API.

The following ILE RPG program sends an inquiry message to the QSYSOPR message queue. It tells the API that it wants the message reply to go to its own program message queue and then uses the Receive Program Message (QMHRCVPM) API to wait for the reply on its program message queue.

      *
      *  Demonstration of using message APIs to do the equivalent of the
      *  SNDUSRMSG CL command in ILE RPG.
      *                                    Scott Klement, July 29, 2004
      *
      *
     D QMHSNDM         PR                  ExtPgm('QMHSNDM')
     D   MsgID                        7A   const
     D   QualMsgF                    20A   const
     D   MsgTxt                   32767A   const options(*varsize)
     D   MsgTxtLen                   10I 0 const
     D   MsgType                     10A   const
     D   MsgQueues                   20A   const dim(50) options(*varsize)
     D   NumQueues                   10I 0 const
     D   RpyQueue                    20A   const
     D   MsgKey                       4A
     D   ErrorCode                 8000A   options(*varsize)
     D   CCSID                       10I 0 const options(*nopass)

     D QMHRCVPM        PR                  ExtPgm('QMHRCVPM')
     D   MsgInfo                  32767A   options(*varsize)
     D   MsgInfoLen                  10I 0 const
     D   Format                       8A   const
     D   StackEntry                  10A   const
     D   StackCount                  10I 0 const
     D   MsgType                     10A   const
     D   MsgKey                       4A   const
     D   WaitTime                    10I 0 const
     D   MsgAction                   10A   const
     D   ErrorCode                 8000A   options(*varsize)

     D RCVM0100        DS                  qualified
     D   BytesRtn                    10I 0
     D   BytesAvail                  10I 0
     D   MsgSev                      10I 0
     D   MsgID                        7A
     D   MsgType                      2A
     D   MsgKey                       4A
     D                                7A
     D   CCSID_status                10I 0
     D   CCSID                       10I 0
     D   MsgDtaLen                   10I 0
     D   MsgDtaAvail                 10I 0
     D   MsgDta                    8000A

     D ErrorCode       ds                  qualified
     D   BytesProv                   10I 0 inz(0)
     D   BytesAvail                  10I 0 inz(0)

     D Message         s            100A   varying
     D MsgKey          s              4A
     D MsgQ            s             20A   dim(1) inz('*SYSOPR')
     D Reply           s            100A

      /free

          // Send an *INQ message to QSYSOPR asking for a reply.
          //
          //  The message will look like the following:
          //
          //   From  . . . :   MYUSERID       07/19/04   14:00:16
          //   Please Reply to this message.
          //     Reply . . :   boing
          //
          //  If you want to remove the "From . . ." line from the
          //  message display, you can do so by specifying a MsgID
          //  and MsgFile as the first two parameters to QMHSNDM API.

            Message = 'Please reply to this message.';

            QMHSNDM( *blanks
                   : *blanks
                   : Message
                   : %len(Message)
                   : '*INQ'
                   : MsgQ
                   : %elem(MsgQ)
                   : '*PGMQ'
                   : MsgKey
                   : ErrorCode );

          // Wait up to 1 hour (3600 seconds) for a reply to the
          // above message. If you change the value of 3600 below to
          // a value of -1, it will wait indefinitely.

            QMHRCVPM( RCVM0100
                    : %size(RCVM0100)
                    : 'RCVM0100'
                    : '*'
                    : 0
                    : '*RPY'
                    : MsgKey
                    : 3600
                    : '*REMOVE'
                    : ErrorCode );

            Reply = %subst(RCVM0100.MsgDta: 1: RCVM0100.MsgDtaLen);

            // The "Reply" Variable should now contain the user's
            // reply.

            *inlr = *on;
      /end-free