Interrupts and communication with external gnuplot drivers

[<tim...@lp...>]

Dear all,

I am working on finalizing wxt running as a separate process so that it 
can work on MacOS. I am trying to figure out what's the best way to 
handle interrupts from the keyboard. First, I'd like to understand how 
gnuplot_x11 does it, but I don't get it:

gnuplot_x11 itself ignores interrupts
    gplt_x11.c, line4813
    signal(SIGINT, SIG_IGN);

gnuplot doesn't, but calls term->reset() and longjmp(). So communication 
with gnuplot_x11 (done with fprintf and fflush on one side, scanf on the 
other) can theoretically be interrupted, but in practice I just never 
saw any communication error. There isn't even a single check for 
returned values from fprintf and scanf. I have tried to hit ctrl-c while 
doing a long plot (something like "set samples 10000000; plot x") and 
never got any error.

Can someone explain this to me ?

Thank you very much.

Best regards,

Timothée Lecomte