A smarter CLI - Innovation by Simplicity

Good command line tools are more important than ever and not just a relict of ancient times in comparison to RIA or GUI applications. Experienced system administrators appreciate their power in sophisticated shell scripts and could probably not manage their environments without them. The question is how can we make command line tools smarter and more powerful than today? This article discusses some ideas and potential implementations always keeping in mind "Do not reinvent the wheel" and "keep it simple".

In the world of free software which made tremendous progress during the last 25 years the CLI (Command Line Interface) never lost it's importance and is still a standard component of well designed applications which expose their APIs and functionality through programming libraries (e.g. in C/C++/C#, Java,...), scripting wrappers (Perl, Python. Ruby, PHP, JavaScript, Tcl, Groovy, Boo, Lua, Lisp, Guile,...), command line utilities, REST/SOAP/XML-RPC/JSON-RPC/D-BUS interfaces and interactive GUI/Web applications.

From a more modern perspective command line tools and the interrelated mini or little languages (e.g. check Eric Raymond's book about The Art of Unix Programming) are special cases of Domain-specific languages (DSL) with the additional focus on interactivity and do not look that old fashioned any more! The syntactic resemblance of command line expressions with functional language constructs e.g. in Haskell or Scala shows further paths of investigation and potential innovations.

The past and future of command line tools