#!/usr/bin/perl

# setenv from within perl to effect parent shell
# actually parent should be more appropriately
# called "adopted" or "step-parent", re execl
# there is one little requirement:
# you should run this program via shell's exec:
#    % exec <scriptname>
#
# this is pure-Perl implementation after Corion's
# comment.

# set env
$ENV{test} = 'TURE';

# ...

# this should be the last statement in your script
# because nothing else will be executed after that
# not even the 'or die ...'
die "no shell!" unless defined($ENV{SHELL});
exec($ENV{SHELL});

__END__