FILETYPES="*.css *.jpg *.jpeg *.gif *.png *.js *.html"
DIRECTORIES="/var/www"

for currentdir in $DIRECTORIES
do
   for extension in $FILETYPES
   do
      find $currentdir -iname $extension -exec bash -c 'PLAINFILE={};GZIPPEDFILE={}.gz; \
         if [ -e $GZIPPEDFILE ]; \
         then   if [ `stat --printf=%Y $PLAINFILE` -gt `stat --printf=%Y $GZIPPEDFILE` ]; \
                then    echo "$GZIPPEDFILE outdated, regenerating"; \
                        gzip -9 -f -c $PLAINFILE > $GZIPPEDFILE; \
                 fi; \
         else echo "$GZIPPEDFILE is missing, creating it"; \
              gzip -9 -c $PLAINFILE > $GZIPPEDFILE; \
         fi' \;
   done
done