GENIE Quick SVN ref

=What is Subversion?=

Subversion (abbreviated SVN) is the successor to CVS. It is closely related to CVS and so many of the commands are the same. For example, Subversion still has the commands checkout, commit and update, except that cvs update is replaced with svn update. Happily this means that there is little re-learning required to use SVN instead of CVS. If they were entirely alike, there would be no need for SVN, however. Subversion addresses a number of the shortcomings of CVS. For example, the command svn move now exists, wehereas files could not be renamed under CVS, without losing their revision history.

=Using Subversion=

First, just as it was with CVS, you will need a Subversion client installed on your machine. If you are using linux, then you will most likely have the command line client already installed. Try typing which svn to see if the clent is in your path. SVN clients exists in both command line and nice GUI forms for just about any operating system. tortoisesvn is popular for windows. SVNx is popular for the Mac. For more links see the links page on this wiki.

Once you have Subversion installed, you will need an username and password. This will allow you to access the GENIE SVN repository. Happily, this is considerably easier than for CVS. You will be prompted for your password when required. SVN caches your password, and so you often do not need to type it.

Another big difference between CVS and SVN is that repositories are accessed through a URL. For example, you might checkout GENIE from SVN by typing: svn checkout http://source.ggy.bris.ac.uk/subversion/genie/trunk --username  ~/genie

=Quick Start=

See the above example, showing how to checkout the trunk of the GENIE repository. (We will cover branches later.) The examples below are for the command line client.

To update an existing checkout, simple cd to the highest-level directory and type: svn update

If you have created a new file, use: svn add

Similarly, to delete a file: svn del

Once you have made your local changes, use: svn commit -m "type your message here"

NB SVN uses version numbers differently to CVS. SVN gives the entire repository a version number and increments this whenever there has been a change. Thus--unlike CVS--individual files do have a version number.

To see the history of a given file, type svn log

To check-out one of the stable releases of GENIE, you can use: svn checkout https://source.ggy.bris.ac.uk/subversion/genie-test/tags/rel-2-1-0 --username  ~/genie

To find out more SVN options type: svn --help