It is perfectly possible to create files in order to run the program in background. On UNIX machines, type a file containing the command as you would type them and just start Gifa by "piping" the file as standard input, and the output on another file. The & sign run the process in background :
% gifa < name_of_the_COM_file > process.out &
DO NOT forget to end the input file with the final ' EXIT N ' which is the end of a normal interactive session (or 'EXIT Y' if you wish to keep the log file). Also you may experience problems if you use interactive shell commands such as 'vi' or even 'more'.
The input in the batch file is entered to the program as a user
would do, so it is different from macro in at least to points :
* control
structures are not allowed
* error conditions will not stop the execution,
but the program will continue, So be careful when deleting important files
within batch files!
Of course any macro can be called during the batch process, without any restriction on control structures.
When running in batch mode it is usually useless (though not forbidden) to activate the display. However if you want to have Gifa running while you are not logged on, you should choose a graphic-less mode. This mode is entered if there is no X_window DISPLAY available. For instance with
unsetenv DISPLAY
Do not forget to adapt a special startup.g macro (for instance in the current disrectory) in order not to launch the standard graphic environment (which would give an error anyway).
It is perfectly possible to plot and print results while in batch mode.