From: Mark Wilson <mwilson13@...>
Date: 2003-08-26T06:59:19+09:00
Subject: Re: Ruby launching system apps?


On Monday, August 25, 2003, at 05:05 PM, Mark J. Reed wrote:

> On Monday, August 25, 2003, at 01:25 PM, Dan wrote:
>> I have a UNIX machine and I want a ruby app that can launch UNIX
>> commands like awk or sed...how would I implement this?
>
> The Shell module lets you invoke UNIX commands, but bear in mind
> that doing so is inefficient,

Avoid premature optimization. If the inefficiency is a problem, 
implement in Ruby. If it is still a problem, extend Ruby with C.

> not portable to non-UNIX machines,

True. The universe of Unix machines is pretty large (including Mac OS 
X). I don't know about Windows with cygwin.

> and likely to cause thread synchronization issues.

The Shell#transact method will handle synchronization.

> Ruby itself can
> do everything awk and sed can do without having to resort to
> running external programs.
> [snip]

True. 'awk' and 'sed' are the least likely candidates, in my opinion, 
for wrapping in the Shell class. However, if you have a shell script 
with functionality you want to use in a Ruby program that you don't 
want to spend the time reimplementing in Ruby, the Shell class may be 
your best bet, at least initially.

Regards,

Mark