From: Massimiliano Mirra <info@...>
Date: 2002-02-04T03:28:48+09:00
Subject: bash-like command splitting (for regexp wizards)

I am trying to split a command line containing several commands that
are concatenated bash-style, i.e. with `||', `&&' and `;' as
separators.  Such separator characters need also be preserved.

I'm using the following code:



dividers = ['\|\|', '&&', ';']

divs = dividers.collect {|div| "(#{div})"}.join('|')

SPLIT_RE = /([^#{divs}]+)|#{divs}/

'ls || cd dir; grep word * && beep'.scan(SPLIT_RE).flatten.compact



It correctly splits the string in the example into:

["ls ", "||", " cd dir", ";", " grep word * ", "&&", " beep"]

However, I'd still like those character sequences to be non-splitting
when they are part of a single or double quote enclosed string.

The code above will choke (of course) when given a string like:

'ls || cd dir; grep "word; sentence" && beep'

It will produce:

["ls ", "||", " cd dir", ";", " grep \"word", ";", " sentence\" ", "&&", " beep"]

Instead of:

["ls ", "||", " cd dir", ";", " grep \"word; sentence\" ", "&&", " beep"]

I've been scratching my head for a while but I'm afraid I've hit the
bottom of my skills with regular expressions.  Any wizard out there
has a recipe for this?


Massimiliano