Basic SCM with
Subversion & Trac
Vishnu Gopal
www.vish.in

Contents
• What, Why and How?
• Subversion Commands
• Demo: Command-line tools
• GUI tools
• Project Layout
• Trac: overview

What?
• Subversion maintains snapshots of the code
repository.
• Allows many people to concurrently work
on a codebase.
• Subversion is source control with a central
repository.
• Usually integrates with a frontend: Trac

Why?
• Continuous incremental backup.
• Ability to recall older code.
• Distributed development.
• Various versions of a single project.
• Tracking bugs, timeline, goals and releases.

Central Repository

How?
• Developers checkout code from the
repository to a local working-copy.
• After making edits, they commit changes.
• At any point, they can revert to an older
version of the codebase.
• They update their local working copy
frequently to keep up with changes.

Work with Subversion

But how does
Subversion work?
• A system to track changes in files.
• The code is initially imported into the
repository.
• Then a special “subversion-aware”
directory is checked-out.
• Developers commit and update.
• Subversion tracks the changesets and the
commit-log.

Common Subversion
Commands
• checkout: Obtain a new working copy.
• import: Import code into repository initially.
• commit: Update repository with changes.
• update: Update working-copy with changes.
• Other commands: revert, move, copy, merge.

Subversion: Demo

GUI Tools
• TortoiseSVN in
Windows
• Right-click a directory:
get a context-menu with
everything in there.
• Useful Integration with
diff and patch.
• Reasonably fast.

Project Layout
• trunk
• All constant development happens here.
• branches
• Special purpose development here.
• tags
• Releases are “tagged” for archiving.

Trac: Demo

Major features of Trac
• Frontend to a Subversion repository.
• Shows the changesets and timeline.
• Has a bug tracker which integrates with the
Subversion commit-log.
• Simple project management.

Some good Subversion
practices
• Follow the branches, tags, trunk structure.
• All code should be in the repository!
• Update code at the start of every day.
• Only commit coherent changes.
• The central repository should always be
consistent.
• Branch as less as possible.

Finis
The end. Questions?