How to create a web scripting language

About 10 years ago I created a version of the Forth language that could be mixed with html like c# or javascript. Apache and IIS may be configured to send a web page with a custom extension to an executable that pre-process the page. The extension I wrote looks for the tags <?4^th ….. ?> in the web page and sends the text between to the 4^th language’s parser. Output from the Forth executable is mixed with the html on the resulting web page and sent by the web server to the user’s browser. The 4^th interpreter injects the html it produces replacing the <?4^th> zzzz z zz ?> tag area.

For example in my 4^th the image below shows a printgreen function written in 4^th in page script and also shows the result seen in the browser.

View source in the browser shows the html that was created and sent from IIS.

What is being done by the 4^th script engine is

· parse the webpage source looking for <?4^th and ?> tags

· extract the text between the tags and send it to the Forth language input buffer

· tell the 4^th language to parse and interpret the commands now in its input buffer

· output the result

The source code for my 4^th scripting language is downloadable at forthwsc.zip (http://dragonsawaken.net/leho/Zen_Soft/Download/forthwsc.zip) The current source is a Visual Studio 2013 project it should compile on older compilers. The output file after the source is compiled is named forthwsc.exe

To enable 4^th in my web server IIS, I follow the steps shown in the images below (I am using version 8 here but Apache and older versions of IIS can do the same thing on windows systems.)

1.) Add a mime type for pages using 4^th. I used .4hf

.4hf a mine type for the file extension of the pages using 4^th script

2.) Give forthwsc.exe permission to run from IIS.

IIS is told that forthwsc.exe is allowed to run.

3.) Create a mapping between *.4hf and FORTH in IIS

Put your forth script files in a directory under wwwroot so they will be found by a url like ‘http://localhost/forthscript/showgreen.4hf’

I include a script designed to test my version of the 4^th language named test4th.4hf in the forthwsc.zip file with the source code.