[ILUG] Bash using locally scoped vars inside while loop.

[Achim Dreyer]

On Tue, 3 Dec 2002, Kevin O' Riordan wrote:

> Date: Tue, 3 Dec 2002 15:20:10 +0000
> From: Kevin O' Riordan <kor at compsoc.com>
> To: ilug at linux.ie
> Subject: [ILUG] Bash using locally scoped vars inside while loop.
> 
> 
> Hi folks,
> 
> when I use a while loop to read piped input, bash seems to use locally
> scoped variables instead of assigning to global variables in that
> script.  So far I've only seen this when I pipe data to a while loop.
> 
> I've put together a script that should explain this a lot better than
> I'm doing.  Basically I'm wondering if I'm seeing a feature, a bug, or
> what.  I'm searching thru the bash bug archives at the mo', and just
> wondering if anyone else has come across this before.
> 
> I'm using bash 2.04.21 here.

Hy, Kev,

.. this is no bug, its a long documented feature! (Good old standard 
Bourne Shell feature ;-))


to get around this you can use stdin redirection with
	exec 1<file
as this happens only with redirected/piped input not with stdin.


-- 
Regards,
Achim Dreyer
--
A. Dreyer, Senior SysAdmin (UNIX&Network) / Internet Security Consultant