I am currently upgrading our intranet Wiki installation to 1.21 (yes, we are one version behind), and I have faced the problem with deprecated message functions, as outlined at mediawiki.org<http://www.mediawiki.org/wiki/Manual:Messages_API#Deprecat…ns>. For instance: Instead of: wfMsg( 'key' ); Do: wfMessage( 'key' )->text(); The problem of course is that the parametrized messages can have arbitrary parameters which can be themselves function calls, making simple regexp substitution infeasible. Well, I figured out that Perl can be used to solve this problem, because Perl allows arbitrary recursive regexps, which are conveniently accessible via the Regexp::Common module. Something like this does the trick: use Regexp::Common; # Convert 'wfMsg->(...)' to 'wfMessage(...)->text()' sub fix_wfMsg ($) { (my $string = shift) =~ s/wfMsg\s*($RE{balanced}{-parens=>'()'})/wfMessage$1->text()/g; return $string; } This method would take the string you provide (should be the entire file contents, to account for multi-line wfMsg calls), and do the appropriate string substitution to replace the deprecated call with the correct one, accounting for nested recursive parentheses. As far as I can tell, the only thing it can get wrong in unbalanced parentheses in comments, e.g. if your line ends in '// unbalanced paren (' type of comment. I hope this helps someone.