use Text::Balanced qw(gen_extract_tagged); my $extract = gen_extract_tagged( 'node\s+\w+\s+\{', # start tag '\}', # end tag '(?s).*?(?=node\s+\w+\s+\{)' # prefix ); # $text is your file contents print indent($extract, $text); sub indent { my( $extract, $text, $depth ) = @_; $text =~ s/^\s+//mg if $depth == 0; if( index($text, '{') == -1 ) { #no more blocks $text =~ s/^/" "x$depth/gme; return $text; } #extract block out of $text my($extracted, $remainder, $prefix, $start, $block, $end) = $extract->($text); $prefix =~ s/^/" "x$depth/gme; my $formatted = $prefix; $formatted .= " " x $depth . $start; # parse the inner block $formatted .= indent($extract, $block, $depth+1) if $block; $formatted .= " " x $depth . $end; # parse what is after this block $formatted .= indent($extract, $remainder, $depth) if $remainder; return $formatted; } #### node myContainer { someParam WhateverWeWerePassed node myNode { fooParam DogPoopMonk node foo2 { stuff more stuff even more stuff node mode2 { stuff } } } } #### node myContainer { someParam WhateverWeWerePassed node myNode { fooParam DogPoopMonk node foo2 { stuff more stuff even more stuff node mode2 { stuff } } } }