use strict; use warnings; use Data::Dump qw/pp dd/; use Test::More; my $wiki = '_/one *two*/ three_ null _/four *five*/ six_ null _/seven *eight*/ nine_'; my $expected = 'one two three null four five six null seven eight nine'; my $pre = qr/(^|\s|>)/; my $post = qr/($|\s|<)/; my %h = ( '*' => 'b' , '/' => 'i' , '_' => 'u' , ); sub tf { s{ $pre ([_*/]) (.*?) \2 (?=$post)}{$1<$h{$2}>$3}xg }; $_=$wiki; my $DBG = 1; diag "IN <= '$wiki'\n\n" if $DBG; for my $i (1..3) { tf(); diag "$i: '$_'\n\n" if $DBG; } is($_,$expected," repeated replace works"); done_testing;