make ikiwiki-transition prefix_directives take a setup file

This is easier to remeber, and less error-prone than passing it all the
pages in the wiki.

debian/NEWS

@@ -110,10 +110,7 @@ ikiwiki (2.40) unstable; urgency=low
   in their setup files.
 
   To convert your wiki to the new syntax, ikiwiki provides a new script
-  ikiwiki-transition.  It will convert preprocessor directives in
-  all files given on the command line.  To convert an entire wiki:
-
-  find wikidir/ -type f -name '*.mdwn' -print0 | xargs -0 ikiwiki-transition prefix_directives
+  ikiwiki-transition.
 
   Even with prefix_directives disabled, ikiwiki now allows an optional '!'
   prefix on preprocessor directives (but still requires a space).  Thus, a

doc/ikiwiki-transition.mdwn

@@ -12,16 +12,15 @@ ikiwiki-transition type ...
 change in ikiwiki syntax. It also handles other transitions not involving
 wiki pages.
 
-# prefix_directives file ...
+# prefix_directives your.setup
 
-The `prefix_directives` mode converts the specified ikiwiki page from
-the old preprocessor directive syntax, requiring a space, to the new
-syntax, prefixed by '!'.
+The `prefix_directives` mode converts all pages from the old preprocessor
+directive syntax, requiring a space, to the new syntax, prefixed by '!'.
 
 Preprocessor directives which already use the new syntax will remain
 unchanged.
 
-Note that if the page contains wiki links with spaces, which some
+Note that if a page contains wiki links with spaces, which some
 older versions of ikiwiki accepted, the prefix_directives transition will
 treat these as preprocessor directives and convert them.
 

doc/plugins/write.mdwn

@@ -486,7 +486,7 @@ use the following hashes, using a page name as the key:
   destination file.
 * `%pagesources` contains the name of the source file for each page.
 
-Also, the %IkiWiki::version variable contains the version number for the
+Also, the `%IkiWiki::version` variable contains the version number for the
 ikiwiki program.
 
 ### Library functions

doc/tips/upgrade_to_3.0.mdwn

@@ -23,7 +23,7 @@ your wiki is upgraded to 3.0.
 You can move these preferences into the setup file by running
 `ikiwiki-transition moveprefs your.setup`
 
-(Make sure you have converted the setuop file to the new format first.)
+(Make sure you have converted the setup file to the new format first.)
 
 ## prefix directives
 
@@ -37,15 +37,10 @@ following to your setup file:
 	
 	prefix_directives => 0,
 
-But it's not hard to convert your wiki to the new syntax. You can use
-[[ikiwiki-transition]]. It will convert preprocessor directives in all
-files given on the command line. To convert an entire wiki:
+To convert to the new syntax, run 
+`ikiwiki-transition prefix_directives your.setup`
 
-	find wikidir/ -type f -name '*.mdwn' -print0 | xargs -0 ikiwiki-transition prefix_directives
-
-Be sure to modify the find to list all pages in the wiki if you're using
-other markup than markdown. You will probably want to commit the changes
-when you're done too.
+(And then commit the changes it makes to pages in your srcdir.)
 
 ## GlobLists
 

ikiwiki-transition

@@ -1,4 +1,4 @@
-#!/usr/bin/perl -i
+#!/usr/bin/perl
 use warnings;
 use strict;
 use IkiWiki;
@@ -42,11 +42,33 @@ sub handle_directive {
 }
 
 sub prefix_directives {
-	$/=undef; # process whole files at once
-	
-	while (<>) {
-		s{$regex}{handle_directive($1, $2, $3, $4)}eg;
-		print;
+	my $setup=shift;
+	if (! defined $setup) {
+		usage();
+	}
+
+	require IkiWiki::Setup;
+	require IkiWiki::Plugin::aggregate;
+
+	%config = IkiWiki::defaultconfig();
+	IkiWiki::Setup::load($setup);
+	IkiWiki::loadplugins();
+	IkiWiki::checkconfig();
+	IkiWiki::loadindex();
+
+	if (! %pagesources) {
+		error "ikiwiki has not built this wiki yet, cannot transition";
+	}
+
+	foreach my $page (values %pagesources) {
+		next unless defined pagetype($page) &&
+		            -f $config{srcdir}."/".$page;
+		my $content=readfile($config{srcdir}."/".$page);
+		my $oldcontent=$content;
+		$content=~s{$regex}{handle_directive($1, $2, $3, $4)}eg;
+		if ($oldcontent ne $content) {
+			writefile($page, $config{srcdir}, $content);
+		}
 	}
 }
 
@@ -109,7 +131,7 @@ sub aggregateinternal {
 	require IkiWiki::Plugin::aggregate;
 
 	%config = IkiWiki::defaultconfig();
-	IkiWiki::Setup::load();
+	IkiWiki::Setup::load($setup);
 	IkiWiki::checkconfig();
 
 	IkiWiki::Plugin::aggregate::migrate_to_internal();
@@ -196,12 +218,12 @@ sub moveprefs {
 sub usage {
 	print STDERR "Usage: ikiwiki-transition type ...\n";
 	print STDERR "Currently supported transition subcommands:\n";
-	print STDERR "\tprefix_directives file ...\n";
-	print STDERR "\tindexdb srcdir\n";
-	print STDERR "\thashpassword srcdir\n";
+	print STDERR "\tprefix_directives setupfile ...\n";
 	print STDERR "\taggregateinternal setupfile\n";
 	print STDERR "\tsetupformat setupfile\n";
 	print STDERR "\tmoveprefs setupfile\n";
+	print STDERR "\thashpassword srcdir\n";
+	print STDERR "\tindexdb srcdir\n";
 	exit 1;
 }