From: Phlip <phlip2005@...>
Date: 2008-07-26T23:04:11+09:00
Subject: Re: if expression or muffle an exception?

aidy wrote:

> I am wondering if this is bad form,
> 
>    begin
>       system("taskkill /im firefox.exe /f")
>     rescue
>      #preventing exception if firefox process does not exist
>     end
> 
>   or should I use an if expression?

You can't use an if (such as if `pgrep firefox.exe` =~ /\d+/) because 
firefox.exe might disappear in the split second between the if and the system.

That's the main difference between things you can if and things you must rescue 
- times when the if would have the wrong side-effects.

-- 
   Phlip