RFE: return exit status from gnuplot process

[djerius]

First off, thanks for this module!

I use Gnuplot::Builder in analysis pipelines, and need to know if there was an error from gnuplot to abort the analysis.

However, it doesn't seem like there's a way to reliably determine if the gnuplot process exited with an error. The return values of the plot() and plot_with() routines are a mix of stdout and stderr, and some gnuplot commands will write to stdout, so a non-empty return from those routines doesn't provide a deterministic means of detecting an error.

It would be great if the exit value of the actual gnuplot process was available. However, it looks like that Gnuplot::Builder::Process::_wait_to_finish doesn't actually wait for the process to end, so it can't retrieve the exit value.

[debug-ito]

Thanks for raising this issue! I agree with you. It would be great if the exit status was available.

I think it should be not so hard to return the exit status, because Gnuplot::Builder already returns the captured STDOUT and STDERR. However, it would be tricky if you want to get the exit status from asynchronous gnuplot processes (i.e. the ones with async option enabled).

Is it ok for you that you can only get the exit status from synchronous gnuplot process and not from asynchronous ones?

BTW, I'm currently not so active on this project, so it could take time for me to handle this issue.

[debug-ito]

I just released Gnuplot::Builder 0.33. The plot_with method now has on_exit option. See https://metacpan.org/release/TOSHIOITO/Gnuplot-Builder-0.33/view/lib/Gnuplot/Builder/Script.pm#%24result-%3D-%24builder-%3Eplot_with(%25args)