Useful Linux links and commands

Useful Linux links:
http://www.cyberciti.biz/faq/howto-linux-add-user-to-group/

http://www.cyberciti.biz/faq/how-to-use-chmod-and-chown-command/
http://www.cyberciti.biz/tips/top-linux-monitoring-tools.html

useful linux commands:
To check folder size: du -s -h
du - Disk usage

S3fs version: s3fs --version


Disk Utilities:
http://www.howtogeek.com/howto/37659/the-beginners-guide-to-linux-disk-utilities/

some commands;
du - disk usage
free -m - checking memory usage
top - load parameters on system

How to count files (get the number of files) under a directory in Linux?

Just perform this command under the directory:

find . -type f | wc -l

and you will get the total number of files under it (recursively). Simply copy and paste that to do the trick.
Or if you just need to count the files directly under the current directory:

ls -f | wc -l

Which is a lot faster than the previous solution.
This should also work on all *nix OS.