Define message descriptions

You can create your own message files and message descriptions. By creating predefined messages, you can use the same message in several procedures or programs but define it only once. You can also change and translate predefined messages into languages other than English (based on the user viewing the messages) without affecting the procedures and programs that use them. If the messages were defined in the procedure or program, the module or program would have to be recompiled when you change the messages.

In addition to creating your own messages and message files, the system message handling function allows you to:

• Create and change message queues (Create Message Queue (CRTMSGQ), Change Message Queue (CHGMSGQ), and Work with Message Queues (WRKMSGQ) commands)
• Create and change message files (Create Message File (CRTMSGF), Change Message File (CHGMSGF) commands)
• Add message descriptions (Add Message Description (ADDMSGD) command)
• Change message descriptions (Change Message Description (CHGMSGD) command)
• Remove message descriptions (Remove Message Description (RMVMSGD) command)
• Send immediate messages (Send Message (SNDMSG), Send Break Message (SNDBRKMSG), Send Program Message (SNDPGMMSG), and Send User Message (SNDUSRMSG) commands)
• Display messages in a message queue (Display Messages (DSPMSG) and Work with Messages (WRKMSG))
• Display message descriptions in a message file (Display Message Description (DSPMSGD) and Work with Message Descriptions (WRKMSGD) commands)
• Use a CL procedure or program to:
  • Send a message to a workstation user or the system operator (Send User Message (SNDUSRMSG) command)
  • Send a message to a message queue (Send Program Message (SNDPGMMSG) command)
  • Receive a message from a message queue (Receive Message (RCVMSG) command)
  • Send a reply for a message to a message queue (Send Reply (SNDRPY) command)
  • Retrieve a message from a message file (Retrieve Message (RTVMSG) command)
  • Remove a message from a message queue (Remove Message (RMVMSG) command)
  • Monitor for escape, notify, and status messages that are sent to a call message queue (Monitor Message (MONMSG) command)
• Use the system reply list to specify the replies for predefined inquiry messages sent by a job (Add Reply List Entry (ADDRPYLE), Change Reply List Entry (CHGRPYLE), Remove Reply List Entry (RMVRPYLE), and Work with Reply List Entry (WRKRPYLE) commands)

When a message is sent, it is defined as one of the following types:

• Informational (*INFO). A message that conveys information about the condition of a function.
• Inquiry (*INQ). A message that conveys information but also asks for a reply.
• Notify (*NOTIFY). A message that describes a condition for which a procedure or program requires corrective action or a reply from its calling procedure or program. A procedure or program can monitor for the arrival of notify messages from the programs or procedures it calls.
• Reply (*RPY). A message that is a response to a received inquiry or notify message.
• Sender's copy (*COPY). A copy of an inquiry or notify message that is kept by the sender.
• Request (*RQS). A message that requests a function from the receiving procedure or program. (For example, a CL command is a request message.)
• Completion (*COMP). A message that conveys completion status of work.
• Diagnostic (*DIAG). A message about errors in the processing of a system function, in an application program, or in input data.
• Status (*STATUS). A message that describes the status of the work done by a procedure or program. A procedure or program can monitor for the arrival of status messages from the program or procedure it calls, but the status message will not appear in a job log. Status messages sent to the external message queue (*EXT) are shown at the display station and can be used to inform the display station user of an operation in progress.
• Escape (*ESCAPE). A message that describes a condition for which a procedure or program must end abnormally. A procedure or program can monitor for the arrival of escape messages from the program or procedure it calls or from the machine. Control does not return to the sending program after an escape message is sent.