Add --changesetup mode that allows easily changing options in a setup file.

2 files changed, 17 insertions, 3 deletions

diff --git a/doc/setup.mdwn b/doc/setup.mdwn
index 03fed3aa9..266222cc3 100644
--- a/doc/setup.mdwn
+++ b/doc/setup.mdwn
@@ -102,6 +102,12 @@ After making changes to this file, you need to tell ikiwiki to use it:
 
 	% ikiwiki -setup foo.setup
 
+Alternatively, you can ask ikiwiki to change settings in the file for you:
+
+	% ikiwiki -changesetup foo.setup -plugin goodstuff
+
+See [[usage]] for more options.
+
 ## Customizing file locations
 
 As a wiki compiler, ikiwiki builds a wiki from files in a source directory,
diff --git a/doc/usage.mdwn b/doc/usage.mdwn
index 2f87d60d5..840d105d2 100644
--- a/doc/usage.mdwn
+++ b/doc/usage.mdwn
@@ -32,14 +32,22 @@ These options control the mode that ikiwiki operates in.
 
 * --setup setupfile
 
-  In setup mode, ikiwiki reads the config file, which is really a perl
-  program that can call ikiwiki internal functions.
-
   The default action when --setup is specified is to automatically generate
   wrappers for a wiki based on data in a setup file, and rebuild the wiki.
   If you only want to build any changed pages, you can use --refresh with
   --setup.
 
+* --changesetup setupfile
+
+  Reads the setup file, adds any configuration changes specified by other
+  options, and writes the new configuration back to the setup file. Also
+  updates any configured wrappers. In this mode, the wiki is not fully
+  rebuilt, unless you also add --rebuild.
+
+  Example, to enable some plugins:
+
+	ikiwiki --changesetup ~/ikiwiki.setup --plugin goodstuff --plugin calendar
+
 * --dumpsetup setupfile
 
   Causes ikiwiki to write to the specified setup file, dumping out