Terminal Management › Line Mode › Reading a Line of Data

Reading a Line of Data

To transfer data from the terminal buffer to program variable storage, issue a READ LINE FROM TERMINAL statement. READ LINE FROM TERMINAL transfers data to your program as follows:

• For line-by-line devices, DC treats the entire screen contents as a single data field; a READ LINE FROM TERMINAL request returns all data to the program at once.
• For 3270-type devices, a READ LINE FROM TERMINAL request returns the first data field on the screen marked for input. DC queues remaining data fields marked for input and passes them back to the program one at a time.

Uses of READ LINE FROM TERMINAL

Typical uses of the READ LINE FROM TERMINAL function are:

• To retrieve any information entered in addition to a task code. That is, for tasks assigned the INPUT attribute, the user can enter data following the task code. For example, if the user enters:

  GETEMP HENDON
  

  DC replaces the task code (GETEMP) with leading blanks and returns the data (HENDON) to the program.
  

• To read the one-line response to a WRITE LINE TO TERMINAL request that has prompted the terminal operator for information. On non-3270 devices, when a READ LINE FROM TERMINAL request is issued after one or more WRITE LINE TO TERMINAL requests, DC writes a question mark (?) to the terminal to indicate that a response is required.
• To enable a program to read formatted 3270-type data fields sequentially. The first READ LINE FROM TERMINAL request returns the first field on the screen that is marked for input. Subsequent READ LINE FROM TERMINAL requests return the remaining fields to the program, one at a time, as illustrated in the example below.

Example of READ LINE FROM TERMINAL

In the figure below, the first READ LINE FROM TERMINAL request returns the value in the first data field; subsequent READ LINE FROM TERMINAL requests return the values in the remaining data fields in the order in which they appear on the screen.