You can use the Jenkins Remote Access API to get a machine-readable description of the current build, including its full change set. The subtlety here is that if you have a 'quiet period' configured, Jenkins may batch multiple commits to the same repository into a single build, so relying on a single revision number is a bit naive.
I like to keep my Subversion post-commit hooks relatively simple and hand things off to the CI server. To do this, I use wget to trigger the build, something like this...
/usr/bin/wget --output-document "-" --timeout=2 \
https://ci.example.com/jenkins/job/JOBID/build?token=MYTOKEN
The job is then configured on the Jenkins side to execute a Python script that leverages the BUILD_URL
environment variable and constructs the URL for the API from that. The URL ends up looking like this:
https://ci.example.com/jenkins/job/JOBID/BUILDID/api/json/
Here's some sample Python code that could be run inside the shell script. I've left out any error handling or HTTP authentication stuff to keep things readable here.
import os
import json
import urllib2
# Make the URL
build_url = os.environ['BUILD_URL']
api = build_url + 'api/json/'
# Call the Jenkins server and figured out what changed
f = urllib2.urlopen(api)
build = json.loads(f.read())
change_set = build['changeSet']
items = change_set['items']
touched = []
for item in items:
touched += item['affectedPaths']