You would need to use a Java Applet with heightened security privileges and a JavaScript API so that JavaScript in the page could read the form data and pass it to the applet. The client computer would need to have the Java plugin and whatever shell you were using installed, and the user would have to accept the above-normal-security-level access rights the applet asked for.
This isn’t in the least bit practical for the WWW and is rather a stretch for a controlled network.
solved Is it Possible to Run Shell Script in Browser