I built a command-line program and I\'d like to build a web interface to let users around the world try the application easily.
I mean, the interface should have textfie
I would make a static HTML screen with a form which, when POSTed, invokes a CGI script in, say, Perl (or whichever language you are familiar with). The script would extract necessary parameters, "feed" them to your CLI program, capture its output via redirection or pipe (depending on the environment) and format the output as the HTML response.
There's the UGUI project: https://ugui.io/
It does seem to have fallen off the maintenance path though, with the latest update in late 2015.
So that you need a web page with input or more input, or select or multi select and buttonto submit arguments to your application. It is not important language about this web page: perl, php, python, is it right? I think php language could be right about your case: it is simple and it does not need any programs or packages like perl or python. If you want simple code, I/somebody could post/s ad hoc code here. If you want a system to install and configure by web interface, you could try getSimple or other simple system.