>perl -wMstrict -le
"my $string_to_search =
   'This part of all of this paart of the string. Paaaaart!';
 ;;
 my $pattern = qr{ (?i) pa+rt }xms;
 my @results = $string_to_search =~ /$pattern/g;
 printf qq{'$_' } for @results;
"
'part' 'paart' 'Paaaaart'