for my $k (sort @hash_array_keys)
{
    print FILEHANDLE $k, $params{$k};
}

##</code><code>##

key1value1
key2value2
key3value3

##</code><code>##

for my $k (sort @hash_array_keys) 
{
    print FILEHANDLE "$k|$params{$k}";
}

##</code><code>##

my %params = $q->Var;
for my $k (sort keys %params)
{
    print FILEHANDLE "$k|$params{$k}";
}