Prompt Message Processing

A prompt message is a message that is issued to the terminal when the program in control requires input from the terminal user. PROMPT information must come from the terminal and cannot be obtained from any other source of input. There are three cases when a request for PROMPT processing is denied by PUTGET:

When the current source of input, as determined by the top element of the input stack, is an in-storage procedure that is not an EXEC command procedure.
When the NOPROMPT attribute is specified in the user's profile table (UPT).
When an EXEC command procedure, executing in the background, does not have a DATA PROMPT entry to satisfy the request or a PROMPT control statement.

When the PUTGET service routine returns control to the program that invoked it, it returns a return code of 12 when no prompting was allowed on a PROMPT request because:

The current source of input is an in-storage list other than an EXEC command procedure.
The NOPROMPT attribute is specified in the user's profile table (UPT).
The current source of input is an EXEC command procedure running in the background, and there is no DATA PROMPT entry to satisfy the request.

If PROMPT processing is enabled, the PUTGET service routine writes the first-level message to the terminal and obtains an input line from either the REXX data stack or the terminal. If the input line is a question mark, PUTGET either returns the next-level message provided or a message informing the user that no information is available. PUTGET continues to respond to each question mark by writing one more second-level message to the terminal until the chain is exhausted. PUTGET then issues a message informing the user that no more information is available. The task then goes into a wait state until the user enters a line. When the user enters a line, PUTGET places the address of the line into the fourth word of the PUTGET parameter block.

Note that for message prompting, PUTGET with TERMGET=EDIT is required.