Once abend processing is appropriately set and a library located, subsequent commands are entirely at the user’s discretion. Commands are executed in sequence as they are read from the terminal. A report of results is printed after each one until END, <PF3>, CLEAR, or “/*” terminates the session.
A DK1TDRVC command begins with a two-character command name and may also contain one or more parameters to be passed to the command. The first two lines of the DK1TDRVC screen are command lines with one field for each part of the TBLBASE command area. Additional parameters, for calls requiring them, are given on subsequent screen lines, delimited by commas. Where a parameter is not given—either fewer fields than the required number of parameters, or some field is null (two delimiters with nothing between them)—then spaces are passed to the TBLBASE API causing the tableBASE default for the field to be used. Parameters shorter than the length available for them in the TBLBASE command area are left-justified and padded with spaces.
Two features of the DK1TDRVC command interface are worth noting before discussion of specific commands:
- If, after a command executes, the user presses the <Enter> key again, the command is re-executed. This is particularly useful for iterative commands such as GN (Get Next row) or FG (Fetch rows matching a Generic key). The first iteration sets the count to the row retrieved and subsequent iterations use and reset that count, resulting in scrolling through the table.
- A blank command area has an effect. Pressing <Enter> with no command executes the PR command, displaying the next seventeen table rows. Pressing <PF1> redisplays the first DK1TDRVC screen with its list of available commands.