| Configuration options / OPTIONS (Runtime) | |
The OPTIONS RUN IN instruction defines the TTY mode to run sub-programs.
OPTIONS RUN IN {FORM|LINE} MODE
When using character terminals, the runtime system recognizes two screen display modes: line mode (IN LINE MODE) and formatted mode (IN FORM MODE). The OPTIONS and RUN statements can explicitly specify a screen mode. The OPTIONS statement can set separate defaults for these statements.
After IN LINE MODE is specified, the terminal is in the same state (in terms of stty options) as when the program began. This usually means that the terminal input is in cooked mode, with interruption enabled, and input not available until after a newline character has been typed.
The IN FORM MODE keywords specify raw mode, in which each character of input becomes available to the program as it is typed or read.
By default, a program operates in line mode, but so many statements take it into formatted mode (including OPTIONS statements that set keys, DISPLAY, OPEN WINDOW, DISPLAY FORM, and other screen interaction statements), that typical programs are actually in formatted mode most of the time.
When the OPTIONS statement specifies RUN IN FORM MODE, the program remains in formatted mode if it currently is in formatted mode, but it does not enter formatted mode if it is currently in line mode.
When the OPTIONS statement specifies RUN IN LINE MODE, the program remains in line mode if it is currently in line mode, and it switches to line mode if it is currently in formatted mode.