use Data::Dumper;

my %patterns = (
  qr/SS\s+(\d+)/
    => sub { $_->{SS} = $1 },
  qr/PL\s+([=#]?)(\d+)([=#])(\d+)/
    => sub { $_->{SP} = $2; $_->{LP} = $4 },
  qr/PV\s+([a-z]?\d+)(\.\d+)?/
    => sub { }, # to be written...
  qr/RL\s+(\d+)([,'"])/
    => sub { $_->{RL} = $1; },
  qr/SA\s+(\d+)/
    => sub { $_->{SA} = $1 },
  qr/DS\s+(\d+)/
    => sub { $_->{DS} = $1 },
  qr/CT\s+([#^]?)\s*(\d+)\s+(\S+)\s+(\S+)/,
    => sub { },
  qr/CL\s+([#^]?)(\d+)\s+(\S+)/,
    => sub { },
);

sub MAGIC {
  my $line = $_[0];
  $_ = {};
  $line =~ s/^\s*//;
LOOP:
  while (length($line)) {
    for my $k (keys %patterns) {
      if ($line =~ s/^$k(?:\s+|\z)//) {
        $patterns{$k}->();
        next LOOP;
      }
    }
    warn "got stuck on: $line\n";
    $_->{leftover} = $line;
    last;
  }
  $_;
}

print Dumper( MAGIC("SS  21   PL 2#3  PV  51.3 CL #110 +0 RL 126' SA 106 DS 93"));
__END__
$VAR1 = {
          'SA' => '106',
          'DS' => '93',
          'RL' => '126',
          'SP' => '2',
          'SS' => '21',
          'LP' => '3'
        };