Tech: Useful unix commands

very useful unix site: http://freeengineer.org/learnUNIXin10minutes.html
create a zipped folder:
zip -r filename.zip filesdir

To change file modes:
find . "replace with pipe" xargs chmod 775

To find the status of processes for user ps204t:
ps -eaf "replace with pipe" grep ps204t

view log file:
tail -f catalina.out

Tar and compress a file in one step
tar cf - target gzip -c > target.tgz