Because you can't run a regex against the variable to untaint the value until execution time.

Maybe I can give a better explanation of what's going on here:
The overall application has an Environment variable pointing to the root of a filesystem/application tree. Lets call it good ol $ENV{FOO}. So far so good, but the perl script needs to pull in a library that is relative to $ENV{FOO}. Let's call that "/bar/lib". There is no way under perl -T that I can call 'use lib "$ENV{FOO}/bar/lib"' because I cannot clear the taint from $ENV{FOO} at compile time.

Hmmm too much english here's some code:

#! /usr/bin/perl -T
$DEZVAR = $ENV{CRROOTWSDIR};

if ($CRROOTWSDIR =~ /^([-\/\w.]+)$/) #Can't evaluate this 
      {                              #until execution
         $MAINPATH = $1
       }
else
      {
        die "Invalid path, please check setenv";
       }

$LIB = "$MAINPATH/cr/cds/comms/x2p";

use lib $LIB; #Must be available at compiletime

blah;
blah;
blah;

[download]

coreolyn Duct tape devotee.
-- That's OO perl, NOT uh-oh perl !-)

In reply to Re: (Ovid) Re: A Quest for Taint by coreolyn
in thread A Quest for Taint by andye

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