In-Storage List

An in-storage list can be either a list of commands or a source data set. It can contain variable-length records (with a length header) or fixed-length records (no header and all records the same length). In either case, no one record on an in-storage list can exceed 256 characters.

When a job is running in the background, the first element in the input stack is a data set element.

Specify an in-storage list and its processing by setting the STORAGE operand type to PROCN, PROCL, or SOURCE.

PROCN or PROCL - Indicates that the in-storage list is a command procedure, which is a list of commands to be executed in the order specified.
If you specify PROCN, requests through GETLINE are read from the in-storage list, but PROMPT requests from the executing Command Processor are suppressed. MODE messages, those messages normally sent to the terminal requesting entry of a command or a subcommand, are not sent; instead, a command is obtained from the in-storage list.

If the PROCL option is specified, the command is displayed at the terminal as it is read from the list.
SOURCE - Indicates that the in-storage list is a source data set. Requests through GETLINE are read from the in-storage list, but PROMPT requests from the executing Command Processor are honored if prompting is allowed, and a line is requested from the terminal. MODE messages are handled the same way as with PROCN or PROCL. No LIST facility is provided with SOURCE records.

If your Command Processor uses the STACK service routine to specify an in-storage list as the input source, you should create the in-storage list in subpool 78. However, if your Command Processor uses the STACK service routine to place either a data set or an in-storage list that is not in subpool 78 on the input stack, the Command Processor must remove the stack element before termination. To remove the stack element, your Command Processor should either:

Issue the STACK macro instruction with the DELETE=TOP operand specified.
Use the GETLINE or PUTGET service routine to process input until end-of-input is reached.

To add an in-storage list element to the input stack, you must build a list storage descriptor (LSD), which contains a description of the in-storage list, and pass its address to the STACK service routine. The STACK service routine then adds the in-storage list element to the input stack. The LSD is described in Building the List Source Descriptor (LSD).

For an example showing how to use the STACK service routine to specify an in-storage list as the input source, see Figure 1.