From: nobu.nokada@...
Date: 2004-06-30T10:57:19+09:00
Subject: Re: [RCR/BUG?] fix system

Hi,

At Wed, 30 Jun 2004 02:22:54 +0900,
Ara.T.Howard wrote in [ruby-talk:104856]:
>    - iff stderr IS NOT redirected you must be prepared to catch Errno::ENOENT in
>      the event your command is not found.
> 
>    - iff stderr IS redirected you will NOT be informed of non-existent commands
>      via an exception and must check $?.exitstatus manually for 127 to
>      determine if the command was not found

Even with stdin or stdout.  And you should remember that
redirecting stderr is not portable.

>    - in all cases you must check $?.exitstatus for success since your command
>      may be found, but fail for other reasons and this will not raise any
>      errors.

Kernel#system returns true when the command succeeded, or false.

One thought:
system could return nil keeping error info when the command
couldn't execute, as perl does.  Then, the current behavior
would moved to Process.start, invoke or something else.

-- 
Nobu Nakada