#!/usr/bin/perl -w
use strict;

# Validate current user
die "Unknown user!" if (!$ENV{LOGIN});

# Load user configuration (from external file or from this script)
my %config;
while (<DATA>)
{
    chomp;
    my ($user, $pref) = /(\w+)\s+(.*)\/perl/;
    $config{$user} = $pref;
}

# Find out the preferred perl version for this user
# If user not seen in the config file, set to default
# path to the latest version of perl
my $path = $config{$ENV{LOGIN}} || "/usr/local/bin";

# Export the modified path for the user
print "export PATH=$path:\${PATH}\n";

__DATA__
roger   /usr/bin/perl
james   /usr/local/bin/perl
thomas  /usr/bin/perl
peter   /usr/perl/bin/perl