untaint path

[Angie Ahl]

Hi everyone.

I'm trying to work out how to untaint a path to passed to modules.

eg/stupidly/long/path/here

contains the folders perl and html

I want to be able the get the following ENV var from apache like so:

local our $HTMLPath = $ENV{HTML_TEMPLATE_ROOT};

And pass it to a module so it can be used to create directories/files 
etc in.

I get the following error (OS X Panther BTW):

Insecure dependency in mkdir while running with -T

obviously I'm not going to turn taint checks off ;) If I set the path 
explicitly mkdir works fine, but that's not very moduler is it;)

Found this in the perldocs, but I don't understand it:

$ENV{'PATH'} = '/bin:/usr/bin';
delete @ENV{'IFS', 'CDPATH', 'ENV', 'BASH_ENV'};
$path = $ENV{'PATH'};       # $path now NOT tainted
Am I going in the right direction? Can anyone give me a clue as to what 
the above actually does. I assume the delete function removes those 
items from ENV, but how does that make it untainted? Makes no sense to 
me.

Cheers

Angie