+#!/usr/bin/perl -i
+use warnings;
+use strict;
+
+my $regex = qr{
+ (\\?) # 1: escape?
+ \[\[(!?) # directive open; 2: optional prefix
+ ([-\w]+) # 3: command
+ ( # 4: the parameters (including initial whitespace)
+ \s+
+ (?:
+ (?:[-\w]+=)? # named parameter key?
+ (?:
+ """.*?""" # triple-quoted value
+ |
+ "[^"]+" # single-quoted value
+ |
+ [^\s\]]+ # unquoted value
+ )
+ \s* # whitespace or end
+ # of directive
+ )
+ *) # 0 or more parameters
+ \]\] # directive closed
+}sx;
+
+sub handle_directive {
+ my $escape = shift;
+ my $prefix = shift;
+ my $directive = shift;
+ my $args = shift;
+
+ if (length $escape) {
+ return "${escape}[[${prefix}${directive}${args}]]"
+ }
+ if ($directive =~ m/^(if|more|table|template|toggleable)$/) {
+ $args =~ s{$regex}{handle_directive($1, $2, $3, $4)}eg;
+ }
+ return "[[!${directive}${args}]]"
+}
+
+sub prefix_directives {
+ $/=undef; # process whole files at once
+
+ while (<>) {
+ s{$regex}{handle_directive($1, $2, $3, $4)}eg;
+ print;
+ }
+}
+
+sub usage {
+ print STDERR "Usage: ikiwiki-transition type file ...\n";
+ print STDERR "Currently supported transition types:\n";
+ print STDERR " prefix_directives\n";
+ exit 1;
+}
+
+usage() unless @ARGV;
+
+my $mode=shift;
+if ($mode eq 'prefix_directives') {
+ prefix_directives(@ARGV);
+}
+else {
+ usage();
+}