The most important commands for SVN

Here are the most important commands for using SVN in the command line on Linux. You have to be inside your local folder where you put the svn else it won’t work (most common source for error “Skipping .'” or “. is not a working copy”).

update

To update your local working copy to the newest version that exists on the server (ALWAYS do this before you start to change things or your teammates will kill you!!):

svn update

add

Files you move into the local working copy folder are not added automatically. If you want the file to be part of the SVN, you have to add it. It works for multiple files or folders, too.

svn add 

delete

To delete files from the repository, first mark them for deletion:

svn rm 

On the next commit, the file will be deleted from the repository and from your local copy! If you want to keep the local copy, do

svn rm --keep-local 

revert

With revert, you can undo pending changes in your working copy (e.g. add, delete) before the next commit.

svn revert 

Also handy in case you forgot what local changes you made and you want to return to the latest “safe” version from the repository.
Note that this does NOT enable you to go back to a previous already-commited version. To do that, you can checkout the specific version of your repository at some other place (with the option -r) and manually get what you need or follow the procedure outlined here.

commit (changes to the repository)

If you have changed a file, added or deleted something and want to put the changes into the SVN you have to commit it, without that the changes are only in your working copy and not on the server!

svn ci -m ""

log

It is good practice to write log messages with commits. You can review these log messages with

svn log

You should do an update of your working copy before this command, otherwise you will not get all messages. In case this is a lot of messages, you can add a limit, e.g., display only the latest 5 log entries:

svn log -l 5

status

To see which files of your working copy haven’t been committed yet:

svn status

Common SVN status codes:

diff

To see what has changed in a file from the last version to the current version:

svn diff 

More resources: You can always use “svn help” to see what else is there or take a look at the excellent book.

A typical SVN session

We assume you have created a working copy and there is already some content in your SVN that you share with others. All of this assumes that you are using some linux shell and are in the folder of your working copy. If you are in the wrong folder else it won’t work (most common source for error “Skipping .'” or “. is not a working copy”).

First thing you do is update (i.e. get the latest changes from the server), in case your teammates changed something. You don’t want to work on an old version!

svn update

Then you open some files, change some things (in "main.adb"), add a new file ("list.adb") and delete a different file ("array.adb"). After two hours work you need a coffee and it’s always a good idea to commit (i.e. send your changes to the server) before taking a longer break. Before you commit, you want to know what changed:

svn status

The message you get will look more or less like this:

M    main.adb
?    list.adb
!    array.adb

This means, you have modified "main.adb", there is a file "list.adb" that SVN doesn’t really know about and "array.adb" should be there, but SVN cannot find it.

If you just commit, only "main.adb" will get changed and on the next update "array.adb" will be restored in your working copy. Why? Because you need to tell SVN explicitly that you want a file to be added or deleted. So let’s do that.

svn add list.adb
svn del array.adb

Now let’s check the status again, the result will be:

M    main.adb
A    list.adb
D    array.adb

We are satisfied and commit the whole thing:

svn ci -m "Replaced array with list, added list.adb, deleted array.adb"

It is always a very good idea to write a meaningful commit message (the parameter -m), so that your teammates know what has been changed. It also makes it easier to go back to a specific version, e.g. the version just before you removed the array.

Creating a SVN working copy (checkout)

You will need to do this once to get the first working copy from the server to your computer.

svn co server_url folder_where_you_want_to_have_your_working_copy

The "server url" isn’t actually a URL like in the internet most of the time. It can be a path to a file (this would work if e.g. if you are inside the IMS and want to access a SVN that is located in a folder that you have mounted) or something with svn+ssh or the like. The one who created the SVN for you should tell you the server URL.

What is SVN?

To say it in very simple terms, SVN allows you to store your files on a server with a change history and have a "working copy" on any computer you like. You only work in your working copy and at some intervals tell SVN to copy the changes you make to the server. SVN will then overwrite the files on the server, but at the same time keep a record of what has changed. This means, that you can always go back to some earlier version – no more need for manual backup!

Also, SVN is great for working in groups. Because the files are on the server and everybody can have his own working copy on his own computer, you need not send around files with the changes you make. Every group member just makes her changes whenever she is ready to get the changes to the group, she just tells SVN to copy them to the server. The other group members only have to update their working copy with the newest version on the server and all have the same version of the code.

That’s actually about it, if you only want to use the basic functionalities. Just some terminology: Creating a working copy is called "checkout", copying code from the server to your working copy is called "update" and copying your changes from your working copy to the server is called "commit".