In need of a bit of shellish magic

[Ted Roche]

I've just put a subversion repository on line and would like to make  
daily backups of it. That's pretty easy, a cron job at 2 AM with:

svnadmin dump /path/to/repos >svndump20060602

However, it would be convenient if the file name incremented year  
month and day automatically. Is there a built in bash feature to  
create a file name like that or should I look at a perl/python script?

For extra points, what's the magic to pipe it through tar? I tried >  
and | followed by tar -czf svndump20060602.tgz, but just haven't  
grokked piping yet, apparently.

Ted Roche
Ted Roche & Associates, LLC
http://www.tedroche.com