my $digits_re = qr{ \d+ }msx;

my $words_re  = qr{
    \S+
    (?: \s+ \S+)*
}msx;

my $print_message_re = qr{
  \A
         Document               [ ]  ( $digits_re ) , 
                                [ ]  ( $words_re  )
    [ ]  owned [ ] by           [ ]  ( $words_re  )
    [ ]  was [ ] printed [ ] on [ ]  ( $words_re  )
    [ ]  via [ ] port           [ ]  ( $words_re  ) \.
    [ ]+ Size [ ] in [ ] bytes: [ ]  ( $digits_re ) ;
    [ ]  pages [ ] printed:     [ ]  ( $digits_re )
    \s*
  \z
}msx;