Locking Files from the Subversion Command Line
Apache Subversion is built around the ‘copy-modify-merge’ model, but you can enforce a ‘lock-modify-unlock’ model if necessary. This can be useful when you’re editing files that cannot be easily merged, for example image files or large binary files.
Creating a Lock
To create a lock, use the ‘svn lock’ command followed by the location and name of the file you wish to lock:
svn lock (working-copy-path/filename)
Keep your colleagues in the loop by adding a log message explaining why you have locked the file. Log messages can be added using the -m switch:
svn lock (working-copy-path/filename) -m “log message”
In this example, we are locking an image file called ‘Logo’ with the log message “Working on logo.”
You can now make changes to the file on your local machine, confident that no one else is committing changes to the repository. Once you have finished modifying the file, you can unlock it using the ‘svn unlock’ command:
svn unlock (working-copy-path/filename)
In this example, we are unlocking the ‘Logo’ file from earlier:
Tip: when you commit back to the repository all locks are automatically released as part of the commit transaction. If you wish to commit without releasing any locks you can use the ‘–no-unlock’ switch to explicitly tell Subversion to maintain the locks:
svn commit –no-unlock (working-copy-path) -m “log message”
In this example we are committing to the repository without lifting the lock, and with the log message “initial draft of logo.”
