{
  'totallyrandom' => 'foo',
  'd' => [
           'baz',
           'bar',
           'uno'
         ],
  'o' => [
           'foo',
           'one',
           'none'
         ]
};
[download]

Which is the default for CGI.pm and others, I want it to be parsed as follows:

{
  'none' => undef,
  'one' => 'uno',
  'foo' => [
             'baz',
             'bar'
           ]
};
[download]

I realize that these requirements are a little odd, but I feel that they happen to suit my application very well, and will be easily usable and so on. However, this requires that I write my own querystring parser which I have done, and now I present it to you in the hopes that some monk can find an error or something thats not optimal so I can fix it now before its 'in production'. It's used in the form of  my $u = new QueryParse; $u->handle( $ENV{QUERY_STRING} );

package QueryParse;
use strict;

sub new
{
  return bless {};
}

sub handle
{
  my $self = shift;
  my $query_string = shift;
  
  if( $query_string eq '')
  {
    local $/ = undef;
    $query_string = <STDIN>;
  }
  
  #o=foo & d=baz & d=qux & o=n & d=o & d=f
  my @query_string = split/[;&]/,$query_string;
  
  my %arg;
  for( my $i = 0; $i < @query_string; $i++ )
  {
    $_ = $query_string[ $i ];
    next unless /^[oO]=/;
    
    my $o = ( split/=/ )[ 1 ];
    my $j = $i + 1;
    my @opts;
    
    while( $j < @query_string )
    {
      $_ = $query_string[ $j ];
      last unless /^[dD]=/;
      my $dat = ( split/=/ )[ 1 ];
      push @opts,$dat;
      $j++;
    }
    
    for( @opts )
    {
      s
      /
        %
        (
          [0-9A-Fa-f]{2}    # match hex escapes ( %2b )
        )
      /
        chr( hex( $1 ) )    # convert in to ascii chars
      /xeg;                  # ignore whitespace, execute code, repeat
    }
    $o =~ s/%([0-9A-Fa-f]{2})/chr( hex( $1 ) )/eg; # same as above
    
    $arg{ $o } = @opts > 1 ? [ @opts ] : $opts[ 0 ];
  }
  
  return %arg;
}

1;
[download]

Two notes, one is that I'm deliberately ignoring options passed via POST in options are already being passed by GET, this is so I can use options in the query_string to specify that say, a file is being uploaded and use some other module to upload the file and interface with it.

The other note is that I deliberately 'inlined' the regex for unescaping the hex codes in the options rather then using the module URI::escape as the author of URI::escape mentions in the docs that 'unescape' does the exact same thing as the regex and calling the function adds anywheres from 40% to 70% slow down.