Introduction to the Form and Menu Language Interpreter (FMLI)

Terminal independence

FMLI uses the UNIX System V terminfo database to determine the values of terminal-dependent capabilities. The default path to this database is /usr/share/lib/terminfo if the environment variable TERMINFO is not set. New terminals not described in this database can be added to the terminfo database under a subdirectory named by the first character in the terminal's name. For example, the 5425 terminal description would be in $TERMINFO/5/5425.

To ensure that the terminal is initialized properly for your FMLI application, include the command

   tput init

in the executable or script that invokes your application. If you choose not to do that, the documentation for your application should remind users to place this command in their .profile file after the TERM variable is set and exported.

NOTE: Terminal attribute settings can be lost when a user returns to an FMLI application after having used a full-screen application executed via the FMLI run built-in utility. To prevent this from happening, the full-screen application can execute tput init before returning to FMLI.

FMLI will work on any asynchronous terminal that

displays 80 characters across
has at least 22 simultaneously visible lines
has a proper terminfo entry in the host computer.

It may be possible to run FMLI on smaller screens if you define the size and position of frames to fit within the screen's limits. However, some elements of screen layout, such as the screen labels for the function keys, may be truncated.

FMLI downloads alternative keystroke sequences into the function keys of some terminals at the user's request. For a discussion, see ``Keyboard and mouse support''.

Recovering after abnormal termination

In the case of an abnormal termination of an FMLI application, users can execute

<CTRL-j> stty sane <CTRL-j>

to restore the screen. Until this is done, user input might not be displayed on the screen, giving the appearance that the computer is hung or down. If the user executes this command to recover, it will also be necessary to execute

   stty tab3

to ensure a sane screen. Borders of frames may be distorted otherwise.