In the previous article, I demonstrated how to install Subversion and set up a shared data repository. This article shows how to access and use the repository using both the command line and a GUI.
Because I use SSH for authentication, I first needed to start the
svn server in tunnel (
-t) mode on the system hosting
the repository. I could simply type this as the user
% svnserve -t
However, that user would lose his prompt. You might be thinking, do this instead:
% svnserve -t &
to start the service in the background. That is better; however, the service
is still attached to
svn's shell, so the service will stop abruptly
if that shell ever closes. In this case, it is better to write a small
shell script owned by the user
svn. I saved mine as
#!/bin/sh #script to start svn server in tunnel mode #first, set correct umask umask 007 #then, use nohup to prevent program from closing if starting shell closes, #send standard output and error to the bit bucket, #and start in the background (to get prompt back) nohup /usr/local/sbin/svnserve -t 2>&1 > /dev/null&
Don't forget to make the script executable and to double-check the permissions and ownership:
% chmod u+x ~svn/repository/conf/svnserve.sh % ls -l ~svn/repository/conf/svnserve.sh -rwxr--r-- 1 svn svn 112 Apr 29 09:36 /usr/home/svn/repository/conf/svnserve.sh
Then, as the user
svn, run the script to start the service:
Unless you configure a mechanism to cache your users' credentials, they will receive authentication prompts every time they view or make a change to the repository. Constant reauthentication can become very irritating very quickly.
Because I'm using the svn+ssh access method, I chose to implement public key
authentication and use
keychain to prevent the user from having to
constantly retype in their passphrase. (Read more about this process at the
IBM Developerworks article OpenSSH Key
Management, part 2, which introduced this utility.)
Here are the steps I used for the user
devel1 who uses FreeBSD
as his desktop. First, I had him generate a public/private key pair using RSA
as the type (
-t) of algorithm. (If you're rusty on encryption
algorithms, you may wish to read through Cryptographic
Terminology 101 first.)
% ssh-keygen -t rsa Generating public/private rsa key pair. Enter file in which to save the key (/home/devel1/.ssh/id_rsa): /usr/home/devel1/.ssh/id_rsa Enter passphrase (empty for no passphrase): type something long but memorable Enter same passphrase again: Your identification has been saved in /usr/home/devel1/.ssh/id_rsa. Your public key has been saved in /usr/home/devel1/.ssh/id_rsa.pub. The key fingerprint is: f6:c2:51:ae:5c:17:91:57:53:c4:58:86:3f:5f:9a email@example.com
I then had
devel1 copy over his new public key to his home
directory on the system hosting the repository; in this case, 10.1.1.1:
% scp ~/.ssh/id_rsa.pub 10.1.1.1:/usr/home/devel1/.ssh
Note: When you do this, make sure you copy over the key with the .pub extension!
Before you can use that key, you have to append it to a file called
authorized_keys. This will require one last
ssh into the
repository system using
devel1's username and password:
% ssh 10.1.1.1 (login using password as usual) % cd ~/.ssh % cat id_rsa.pub >> authorized_keys % exit
Finally, I had
devel1 verify that SSH was using his public key
% ssh 10.1.1.1
This time, instead prompting him for his password, it prompted for his passphrase:
Enter passphrase for key '/home/devel1/.ssh/id_rsa': % exit
Now that the public key works on the repository system, it's time to deal
with the private key. On
% ssh-add ~/.ssh/id_rsa Enter passphrase for .ssh/id_rsa: Identity added: .ssh/id_rsa (.ssh/id_rsa)
Finally, I set up
keychain to cache the credentials. As
# pkg_add -r keychain
Then, I had
devel1 add these lines to his ~/.cshrc
`eval ssh-agent` /usr/local/bin/keychain /usr/home/devel1/.ssh/id_rsa source /usr/home/devel1/.ssh-agent > /dev/null
csh about the change:
% source ~/.cshrc KeyChain 18.104.22.168; http://www.gentoo.org/proj/en/keychain/ Copyright 2002-2004 Gentoo Foundation; Distributed under the GPL * Initializing /home/devel1/.keychain/hostname.org-csh file... * Adding 1 ssh key(s)... Enter passphrase for /usr/home/devel1/.ssh/id_rsa: * Identity added: /usr/home/devel1/.ssh/id_rsa (/usr/home/devel1/.ssh/id_rsa)
devel1 entered his passphrase. Now, he will see no prompts for
any credentials for the entirety of his session as "keychain" will inform the
SSH server that the identity has not changed.
Note: If your users instead use the
bash shell, the
DeveloperWorks article has the lines required for .bash_profile.
Now that the server is running and authentication works, it's time to access
the repository. Because
devel1 prefers to work at the command
line, I'll demonstrate the
svn commands he'll use most often.
I'll then install a GUI for
devel2 and demonstrate that it is
merely a front end for the same commands.
Before you can make any changes to the repository, you must download a working copy to your system. In Subversion terms, this is a checkout. If you always work from the same PC, you need to run this command only once. The syntax is:
% svn checkout svn+ssh://10.1.1.1/usr/home/svn/repository/www A www/apache A www/apache/index.html <snip long output> Checked out revision 1.
The above command copied the entire repository to a directory called
devel1's home directory. This is his working
copy. If you wish to specify an alternate location for your working copy,
place it at the end of the command. For example, this will create a working
copy called mycopy:
% svn checkout svn+ssh://10.1.1.1/usr/home/svn/repository/www mycopy
Once you've checked out your working copy, you can modify its files, add
files, and remove files. In order to use any
svn commands, your
present working directory will have to be somewhere within your working copy.
For example, if I try to view the log from
directory, I'll receive this error:
% pwd /usr/home/devel1 % svn log svn: '.' is not a working copy
However, if I
cd to the working copy, in this case
% cd www % svn log
svn command will work. If you get a "working copy"
cd to your working copy and try again.
It is very important that you always run this command before making any changes to your working copy:
% svn update At revision 1.
update command checks your working copy against the
repository to ensure that they are the same. Because I just checked out my
working copy, there aren't any differences. However, if someone else had made
any changes to the repository, that command would download those changes and
merge them into my working copy.
Suppose that you want to add a file to a repository. After you have created
the file somewhere in your working copy, use
svn add to add it.
Here, I wish to add a test file called ~devel1/www/test:
% pwd /usr/home/devel1/www % svn add test A test
This has added the file, but it didn't upload it to the main repository
yet. That won't happen until I
commit the change:
% svn commit -m "test file added by devel1" Adding test Transmitting file data . Committed revision 2.
Note that I used the
-m switch to add a message to the log and
that the revision number has incremented.
You don't have to commit after every change, as
svn will queue
up your changes and commit everything when you issue
However, if you're the forgetful sort or if many people work on the repository
simultaneously, it doesn't do any harm to
commit often. If you do
queue up a lot of changes, don't forget to mention them all when you add your
message to the log.
Note that the main repository is now at revision 2, but my working copy is
still at revision 1. For example, if I type
svn log, I won't see
my comment. However, if I
update, I will:
% svn update At revision 2. % svn log ------------------------------------------------------------------ r2 | devel1 | 2005-05-02 11:37:02 -0400 (Mon, 02 May 2005) | 1 line test file added by devel1 ------------------------------------------------------------------ r1 | svn | 2005-04-29 08:31:47 -0400 (Fri, 29 Apr 2005) | 1 line initial import ------------------------------------------------------------------
You can also delete files. However, don't use
rm to do so. The
proper method is
% ls apache default.php en test % svn delete test D test % ls apache default.php en
svn removed that file from my working copy? The
D also indicates that issuing a
commit will delete
the file from the repository:
% svn commit -m "removed test file" Deleting test Committed revision 4.
Why is it showing revision 4 when I'm at revision 2? Because someone else
has committed a change since the last time I ran
svn update. Let's
see what it is:
% svn update U frameset.html Updated to revision 4.
Note that a new (added) file starts with
A, a deleted file
D, and a modified (updated) file starts with
U. Someone else modified the file frameset.html before I
committed my change.
svn log would tell me who, and I would see
that my change was revision 4 and the other person's change was revision 3.
I could get exact details on the file's modifications by issuing a
diff on revision 3:
% svn diff -r 3 Index: en/frameset.html ================================================================= --- en/frameset.html (revision 3) +++ en/frameset.html (working copy) @@ -2,10 +2,10 @@ <snip> -<frameset rows="21%, 79%" border="0"> +<frameset rows=27%,73%" border="0"> <snip other changes>
You'll see that this is like any
diff output. In this snippet,
a single line has changed from its original values of 21 percent and 79 percent to new values
of 27 percent and 73 percent.
If you wish to modify an existing file, simply make your edits. You don't
svn add, as the file already exists. When you issue your
svn commit, your modifications will upload to the repository.
Do remember to add a useful message to remind yourself and others of the edits
Here are the commands you'll use most often:
svn update--Always do this before changing your working copy
or if a
commit indicates a higher revision number than you were
svn add--Whenever you create a file; you have to create the
file before you can add it.
svn delete--When you wish to delete a file. (Don't use
rm in your working copy!)
svn commit--To upload your changes. Include
with a message; otherwise,
svn will open the
so you can add your comments to the log.
svn log--To view the log of changes.
svn diff -r #--To see details of the changes made by the
Chapter 9 of the SVN
book gives details and examples for all of the
I originally planned to use
esvn as the GUI, but found that the
current version truncated the name of the repository, which made it impossible
to use any
svn commands. However, I had good luck with
Installing on FreeBSD was a simple matter of:
# pkg_add -r rapidsvn
There are also binaries available as a Debian .deb, a Red Hat RPM, and a Windows installer.
keychain set up and working, I had
him open up
rapidsvn and choose Checkout from the Repository menu.
(Figure 1). He typed the same URL that
devel1 had used at the
command line, and chose to save his working copy as www. Selecting Add
to Bookmarks ensures that the copy will show up as a tree in the left pane.
Figure 1. Checking out with
rapidsvn--click for full-size image
Once he had a working copy,
devel2 went into the View menu and
chose Preferences, then Programs. Here he defined his favorite editor and
file explorer. That made it very easy for him to navigate between existing files
on his system and his working copy.
The Modify menu contains the most often used
Each has either a Ctrl-letter or a function key shortcut for quick
devel1 learned how to use the various
svn commands, he quickly became comfortable with the interface and was able to return to his real work of web development.
svn provides a feature-rich yet easy-to-learn method for
sharing a project's files between users. Edits are simple to track, and if need
be, users can revert any file to an earlier revision. While I've covered the
most used commands in this article, refer to the Subversion web site for more
information on how to get the most out of your repository.
Dru Lavigne is a network and systems administrator, IT instructor, author and international speaker. She has over a decade of experience administering and teaching Netware, Microsoft, Cisco, Checkpoint, SCO, Solaris, Linux, and BSD systems. A prolific author, she pens the popular FreeBSD Basics column for O'Reilly and is author of BSD Hacks and The Best of FreeBSD Basics.
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