if (...) {
   if (...) {
       if (...) {
           if (...) {
               .... 
           } else {
               return 0;
           }
       } else {
           return 0;
       }
   } else {
       return 0;
   }
} else {
    return 0;
}

##</code><code>##

    ($msg =~ /^([^\s]+)/) or return 0;
    $alias = $1;

    ($msg =~ /-address="([^"]+)"/) or return 0;
    $address = $1;

    ($msg =~ /-port="([^"]+)"/) or return 0;
    $port = $1;

    ($msg =~ /-nick="([^"]+)"/) or return 0;
    $nick = $1;

    ($msg =~ /-password="([^"]+)"/) or return 0;
    $password = $1;

    ($msg =~ /-prefix="([^"]+)"/) or return 0;
    $prefix = $1;

    ($msg =~ /-auto_connect="([^"]+)"/) or return 0;
    $auto_connect = $1;

##</code><code>##

   # Regular expressions to apply
   my $a_regexes = [
       qr/^([^\s]+)/,
       qr/-address="([^"]+)"/,
       qr/-port="([^"]+)"/,
       qr/-nick="([^"]+)"/,
       qr/-password="([^"]+)"/,
       qr/-prefix="([^"]+)"/,
       qr/-auto_connect="([^"]+)"/,
   ];

   # Construct an array of resulting regex captures
   my @results = ( );

   # Save each pattern (returning if missing from regex)
   foreach my $regex (@$a_regexes) {
       if ($msg !~ /$regex/) {
           return 0;
       }
       push @results, $1;
   }

   # Assign to the desired variables
   my ($alias, $address, $port, $nick,
       $password, $prefix, $auto_connect) = @results;

##</code><code>##

   # Define the tokens we wish to extract
   my @tokens = qw( address port nick password prefix auto_connect );

   # First token is a special case
   my $alias = ($msg =~ /^(\S+)\s*/)? $1: "";
   $alias or return 0;

   # Construct an array of resulting regex captures
   my @results = ( );

   # Construct the regex from each token, and capture the value
   foreach my $token (@tokens) {
      ($msg =~ /-${token}="([^"]+)"/ or return 0;
      push @results, $1;
   }

   # Assign to the desired variables
   my ($address, $port, $nick, $password, $prefix, $auto_connect) = @results;