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--- lirec:version_control_guide [2009-02-04 13:51] – 81.188.78.24
+++ lirec:version_control_guide [2009-02-04 15:13] – davegriffiths
@@ Line 3: / Line 3: @@
 [[:Version control]] is a way to develop software in a scalable way. Even if you are the only person working on a project, it enables you to write code with more confidence, as you know you have every change tracked - no more wondering what you did which broke everything, as you can find out easily. You can also tag points in development for retrieval later on - it's a good idea to do this before working on big structural changes which could cause instability while you work on them.
-Version control can be also be used in order to share development between groups of people, up to hundreds of developers. It takes care of merging all the changes together (which often worries people new to version control) but it generally works well, and if it finds a confusing case (normally where two developers have changed the same line of code) it asks you to confirm what it's doing.
+Version control can be also be used in order to share development between groups of people, up to hundreds of developers. It takes care of merging all the changes together, which often worries people new to version control but it generally works well, and if it finds a confusing case (normally where two developers have changed the same line of code) it asks you to confirm what it's doing.
 =====Usage pattern=====
+Before we get into using svn, there are some basic usage patterns which are common to all revision control systems. You get the most out of version control if you make it part of your daily programming routine.
+The general idea is that code lives on a remote server, and you keep a local copy of the source on your hard drive. You edit files and compile as normal then 'commit' your changes to the remote server. You also need to periodically update your code to get changes that other people have made.
+The smaller the changes, and the more frequently you commit code, the less hassle you will cause for yourself and other people in the long run. This is an example day's work:
+  * First thing, updated to get the latest code
+  * Fixed a bug
+  * Commit with a message explaining what you fixed
+  * Start working on a new feature
+  * While doing that, found and fixed another bug
+  * Commit the files you changed to fix the bug (not the ones involved with the new feature)
+  * Finish working on the new feature
+  * Commit with a message explaining what the new feature is
+  * Update the code again
+  * Start working on the next feature
+And so on. The messages are important - they only need to be short one liners, but they need to explain why you changed what you did - but there is no need to explain what the changes were (you can tell this from the code, so it would be redundant information).
+=====SVN Basics=====
+I've set up the lirec svn repository with a dummy project called 'sandbox' that you can play with and break to your heart's content. This guide is written for the commandline version of svn, if you prefer buttons to press, read through this document anyway as the concepts are the same, and then have a look at [[http://tortoisesvn.tigris.org/|Tortoise SVN]]. [TODO - update this with a guide for using that.]
+Firstly svn likes to know what editor you like to use so it can launch it to ask you to input comments for your code commits. Put this in your .bashrc:
+<code>export EDITOR=vi</code>
+Or the equivalent in windows [TODO].
+====Getting the code====
+Firstly go to a directory where you want to keep your code and run:
+<code>svn checkout --username your-lirec-username http://svn.lirec.eu/</code>
+Obviously replacing "your-lirec-username". The username is required to link the changes you make to you.
+====Make some changes====
+cd into 'sandbox' and edit the impressive application you'll find there. When you've saved run:
+<code>svn commit</code>
+This will pop up the editor you specified earlier. Add a nice informative message, save the file, and close the editor. If all is well, your change is now sent to the svn server. If, as sometimes happens to me, you realise at this point that you've forgotten something, close the editor without saving - svn will then ask you if you want to abort the commit.
+====Adding files====
+<code>svn add filename</code>
+Will add individual files to the repository, or recursively add files in a directory.
+====Adding directories and moving files====
+<code>svn mkdir mydirectory</code>
+Will make a new empty directory registered with svn.
+<code>svn mv /path/to/file /another/path/to/file</code>
+Will move or rename a file.
+====Updating====
+<code>svn update</code>