Subversion (SVN) is a version control system that allows developers to manage changes to their codebase over time. One of the key features of SVN is branching, which enables developers to create separate lines of development for their project. In this tutorial, we will cover the basics of creating branches in SVN.
Branching in SVN is facilitated by a lightweight and efficient copying facility. Essentially, branching and tagging are the same operation – copying a whole folder in the repository to somewhere else in the repository using the svn copy command. The meaning of the copied folder depends on the convention used by the development team.
To create a branch, you need to set up a folder structure within your repository to support your style. A common approach is to have top-level folders called tags, branches, and trunk. You can then copy your whole trunk (or sub-sets) into the tags and/or branches folders.
Here’s an example of how to create a branch using the svn copy command:
$ svn copy https://host.example.com/repos/project/trunk \
https://host.example.com/repos/project/branches/NAME_OF_BRANCH \
-m "Creating a branch of project"
In this example, we’re copying the trunk folder to a new location in the branches folder, creating a new branch called NAME_OF_BRANCH. The -m option specifies a log message for the operation.
When creating branches, it’s essential to have a good naming convention that tells you why the branch was made and whether it is still relevant. You should also consider ways of archiving branches that are obsolete.
To switch to the newly created branch, use the svn switch command:
$ svn switch https://host.example.com/repos/project/branches/NAME_OF_BRANCH
This will update your working copy to reflect the changes in the new branch.
If you have local changes in your trunk and want to sync them with the new branch, you can use rsync (but be aware that using rsync directly on SVN working copies is not recommended as it may cause issues with the .svn metadata). Instead, commit your changes to the trunk first and then merge them into the branch.
To get the correct URLs quickly, run svn info to display useful information about the current checked-out branch. The URL should give you the URL you need to copy from.
In summary, creating branches in SVN is a straightforward process that involves copying a folder in the repository using the svn copy command. By following best practices for naming conventions and folder structure, you can effectively manage your project’s development workflow.