#!/usr/bin/perl -w

# Environment variables :
print " --- ENV hash --- \n";
foreach my $key (keys %ENV) {
  print " \$ENV{ $key } => '" . $ENV{$key} ."'\n";
}

# Using the back-quotes
my $dir = `pwd`;  # /bin/pwd is "print working directory".
print " current working directory is $dir \n";