I am relatively new to Subversion — well, two years into using it now, but this is the first project I have used it on. Subversion, like any tool, has its quirks and works best when you really know how to use it. When I started, I treated the “trunk/branches/tags” directory structure exactly like a directory structure. It took me a little playing around until I stumbled on what I would call a best practice. When I checkout a new project, I do it like so:

svn co http://domain.com/svnroot/project/trunk project

That way, when I go to the project directory, I do not have to then go into the trunk directory to get to my files. Saving an extra directory level is not the best benefit though. When I set up my IDE (yes, I use an IDE), I put the IDE files in that one directory and do not have to recreate them for each branch or tag that I might check out. I essentially treat the “trunk/branches/tags” part of the directory as pure metadata, which makes perfect sense to me.

When I switched over to this system, there was one big drawback. I could not easily tell where I am just by looking at my prompt. I had to run svn info | grep URL to see if I was on a branch. So instead of letting my prompt handicap me, I decided to get smart about my prompt. Using bash, my prompt used to look like this:

jeff:/opt/pose/main/report/src/main/java

but now it looks like this (supercharged with Subversion metadata):

jeff:/opt/pose/main/report/src/main/java [SVN: /main/report/trunk]

I’m no bash expert, so I dug around on the web and learned a bit about how PROMPT_COMMAND works. Here is what I have in my .bash_profile now:


function spwd ()
{
stat .svn > /dev/null 2>&1;
if [ "$?" == "0" ]; then
SURL=`svn info | grep URL | perl -pe 's/URL: (.*)/\1/'`;
if [ `echo ${SURL} | grep -E "branches|tags"` ]; then
SVER=`echo ${SURL} | perl -pe 's{.*/(branches|tags)/(.*)}{\1/\2}' | cut -d/ -f1-2`;
SPTH=`echo ${SURL} | perl -pe 's{.*svnroot/(.*)/(branches|tags)/.*}{/\1}'`;
SPWD="${SPTH}/${SVER}";
else
SPWD=`echo ${SURL} | perl -pe 's{.*svnroot/(.*)/trunk(.*)}{/\1/trunk}'`;
fi;
export PS1="\u:\w [SVN: $SPWD]\n$ ";
else
export PS1="\u:\w $ ";
fi
}
export PROMPT_COMMAND=spwd


It may not be the most efficient way to do it, but it sure works well and lets me know in an instant what trunk, branch or tag I happen to be working on at that very moment.