First, I would like to clarify a quick question I have, am I right in thinking that files in svn repo don't actually exist in the heirarchical structure you see when you check them out?
I have tried to use svn export ~/svn/project1 ~/public_html/project1 but it didn't work.
What I actually want is to have the export command automatically executed when I do a commit so that I can see my changes immediately in a web browser.
am I right in thinking that files in svn repo don't actually exist in the heirarchical structure you see when you check them out
Correct... they actually exist in a DB of sorts in the repository directory. However you can invoke svn export on a working copy or a respoitory url. So lets say your repo is on the system at /svn/myproject and you have a working copy of trunk at ~/myproject then either of the folloring commabds will export properly:
svn export --force ~/myproject ~/public_html
svn export --force file:///svn/myproject/trunk ~/public_html
ofcourse you can subsitute the svn, http, or svn+ssh for the file protocol depending on how your access is set up.