This approach will only gets you deeper and deeper in more and more complicated regexes and levels within levels of if ... then ... else ... constructs. And if you add another command you have to start all over.

Better then to write a real and robust parser for your command language.

First you have to invent the grammar and syntax for your commands. Once you have that structure made, you can start thinking of writing the parser:

  1. Split the command into tokens
  2. Check each token for being a valid command or parameter (here the "partial" command regex can be used!)
  3. (re)assemble the tokens into a canonical format, which your backend engine can directly understand.

Higher Order Perl has some good examples how to do this.

CountZero

A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James

In reply to Re: Regex - Matching prefixes of a word by CountZero
in thread Regex - Matching prefixes of a word by SuicideJunkie

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