Shell Programming and Scripting

Hello dear Community,
I have a task to wrtie a script which will gzip not zipped files in a directory and it´s subdirectories. I succeeded in gzippung the directory but not the subdirectories:

Code:

#/bin/bash
#go to the directory where to zip
cd $1
#Zip unzipped files
for i in `ls | xargs file | awk -F: ' ! /gzip/{print $1}'`
do
gzip $i

done

I am a newby at scriptiung. Found the above script in parts somwehre in the web.

What do I must add to let the script zip files in subdirectories of the directory aswell as files in the directory.
pls Help

From the man page of gzip: It will even automagically skip files it know are already compressed using gzip.

Thanks a lot
it worked just fine for me

Code:

...
gzip -r $i
...