Subversion Update Tips

Subversion has been an excellent tool for version control, but certainly with its own frustrations.

One of these has been knowing where you are (or, rather, your working copy is) in relation to what is what's on the server's repository.

Version 1.5, approximately, introduced a few changes which make this much simpler. At least with v1.6 you can do this, assuming you are in a subdirectory under one in svn control:

$ <strong>svn ls ^/tags</strong>
1.5/
[...]
3.0/
3.0.1/
3.0.2/
3.0.3/
$

Huzzah! Subversion replaces the caret with "the root URL of the repository for this checkout" -- I sure wish I had known this a lot earlier. Now I can see what other tagged versions are available.

Some of you may have guessed my working copy was of Wordpress. Here's how we can see exactly what's going on in a particular tagged version, without actually checking it out:

$ <strong>svn ls ^/tags/3.0.3/wp-includes/ -v</strong>
 16803 westi                 Dec 08 10:50 ./
 13211 nacin                 Feb 18  2010 Text/
 8149 westi           10928 Jun 20  2008 atomlib.php
 15148 nacin           11549 Jun 05  2010 author-template.php
 12525 ryan             9624 Dec 23  2009 bookmark-template.php
[...]

Ah, you say, but I have the tagged version I want... I just want to know what will happen if I type svn update ...? Well try this:

$ <strong>svn diff -r HEAD</strong>

That will show you the differences between your current working copy and the latest edition (head) of the currently checked out version... which is the differences that will be applied if you did an update.

OK, now I'm ready to switch my version... this used to be a bit of a pain, having to copy the URL... but now we can just do:

$ <strong>svn sw ^/tags/3/0.3</strong>
<em>or maybe</em>
$ <strong>svn sw ^/trunk</strong>