Version Control with Subversion - Electrical and Computer ...

Chapter 3. Guided Tour
Help!
Import
Now we will go into the details of using Subversion. By the time you reach the end of this chapter, you
will be able to perform almost all the tasks you need to use Subversion in a normal day's work. You'll
start with an initial checkout of your code, and walk through making changes and examining those
changes. You'll also see how to bring changes made by others into your working copy, examine them,
and work through any conflicts that might arise.
Note that this chapter is not meant to be an exhaustive list of all Subversion's commands—rather, it's a
conversational introduction to the most common Subversion tasks you'll encounter. This chapter assumes
that you've read and understood Chapter 2, Basic Concepts and are familiar with the general model
of Subversion. For a complete reference of all commands, see Chapter 9, Subversion Complete Reference.
Before reading on, here is the most important command you'll ever need when using Subversion: svn
help. The Subversion command-line client is self-documenting—at any time, a quick svn help
will describe the syntax, switches, and behavior of the subcommand.
You use svn import to import a new project into a Subversion repository. While this is most likely the
very first thing you will do when you set up your Subversion server, it's not something that happens very
often. For a detailed description of import, see the section called “svn import” later in this chapter.
Revisions: Numbers, Keywords, and Dates, Oh
My!
Before we go on, you should know a bit about how to identify a particular revision in your repository.
As you learned in the section called “Revisions”, a revision is a “snapshot” of the repository at a particular
moment in time. As you continue to commit and grow your repository, you need a mechanism for
identifying these snapshots.
You specify these revisions by using the --revision (-r) switch plus the revision you want (svn -
-revision REV) or you can specify a range by separating two revisions with a colon (svn --revision
REV1:REV2). And Subversion lets you refer to these revisions by number, keyword, or date.
Revision Numbers
When you create a new Subversion repository, it begins its life at revision zero and each successive
commit increases the revision number by one. After your commit completes, the Subversion client informs
you of the new revision number:
$ svn commit --message "Corrected number of cheese slices."
Sending sandwich.txt
Transmitting file data .
Committed revision 3.
If at any point in the future you want to refer to that revision (we'll see how and why we might want to
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