hooks

git hooks will fire at various times, depending on the name. You can find example hooks inside .git/hooks/ in any git project.

You probably wouldn't want to do this all the time. An example where it is very handy is if you might be working on a project that is a walkthrough from a book or web site. Although you can commit your code, it may depend on the state of the database. A prime example would be a drupal project.

#!/bin/sh
 
# adds a compressed database dump to every commit
echo "creating compressed database dump..."
mysqldump -umysqluser -pmysqlpass databasename | gzip > filename.gz
git add filename.gz
exit $?

* http://www.kernel.org/pub/software/scm/git/docs/githooks.html