dd/sh: The One True Programming Language

Question

dd/sh is a simple, compact programming language which can do everything although not always the way you are used to. Its name derives from the Unix program dd and the Bourne Shell, sh. Traditionally, the language was used to do text processing, and its first application, a simple text editor, is the best example of the language. The original article about the text editor also contains an historical introduction to the language. We plan to develop more applications, and we will display them here. Just now, here's what we have:

• Just to show that you can do everything in DD/SH, we proudly exhibit a Turing machine.
• A web server in DD/SH: the source code is here
• To simplify porting of INTERCAL programs to DD/SH, we have provided a set of functions and an example program to perform INTERCAL calculations (interleave, select, and the unary logical operators) in DD/SH.
• We are working on a regular expression compiler but this is being delayed while I work on saner things.

Laurent Vogel has written a shell script to factorise numbers, which however doesn't work with a vanilla Bourne shell (such as the one installed here on Freeshell). It does work with bash. If you wish to send any comment about this product, you can obtain our email address running this program (requires a reasonable operating system with at least an implementation of the Bourne Shell and of course DD). To help bypassing spam filters, include DDSH somewhere in the Subject.