Linux Commands
sudo - Super User DO
su - change user
chgrp - change Gourp
chown - change Owner
chmod - change permissions

  • rwx = 111 in binary = 7
  • rw- = 110 in binary = 6
  • r-x = 101 in binary = 5
  • r– = 100 in binary = 4

passwd - Change password
tar -xzvf filename - unxip
echo “Some String” | md5sum
yum update - updates linux
sudo passwd root - Enables disabled root account
sudo passwd -l root - Disables root account
Emacs Commands

Wireless Setup

Apache

PHP

Dovecot

Postfix

Logwatch

Logwatch is a tool that will monitor your server's logs and email the administrator a digest on a daily basis.

$ sudo apt-get update
$ sudo apt-get install logwatch

For Ubuntu systems with apache server:
edit /usr/share/logwatch/dist.conf/logfiles/http.conf
See Here