use strict; use warnings; 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 %h = ( '*' => 'b' , '/' => 'i' , '_' => 'u' , ); my $DBG = 1; sub flip { my $s = shift; my $z = $h{$s}; $h{$s} = $z =~ /\// ? substr ($z, 1, 1) : "/$z"; return "<$z>"; } sub tf { diag "Pre: '$_'\n\n" if $DBG; s{([_*/])}{flip($1)}eg }; $_ = $wiki; diag "IN <= '$wiki'\n\n" if $DBG; tf(); is ($_, $expected, " repeated replace works"); done_testing;