use CGI;

my $cgi = CGI->new;

# using a list of parameters
for my $key ($cgi->param()) {
  printf "%s=%s\n", $key, $cgi->param($key);
}

# Using a hash of key => value
my %params = $cgi->Vars();
while (my ($key, $value) = each %params) {
  printf "%s=%s\n", $key, $value;
}