Drush is a command line to manage Drupal. These are some usage example.
# create a list of enabled modules
drush sm --pipe --status=enabled
# create txt file which contains a list of enabled modules
drush sm --pipe --status=enabled | cat > modules_enabled.txt
# --- SVN ----
# Remove all .svn folders in a directory tree
find . -name ".svn" -type d -exec rm -rf {} \;