Find out non-system users

alias lsusers='getent passwd | tr ":" " " | awk "\$3 >= $(grep UID_MIN /etc/login.defs | cut -d " " -f 2) { print \$1 }" | sort'

Above command to list non-system users. It should be portable though won't work on systems without the getent command.

Changing file extensions

#rename 's/.html$/.php/' *.html

This will change the extension of every .html file in your PWD to .php.

Configure AIDE

What is AIDE?

AIDE (Advanced Intrusion Detection Environment) is a free replacement for Tripwire. It does the same things as the semi-free Tripwire and more. There are other free replacements available so why build a new one? All the other replacements do not achieve the level of Tripwire. And I wanted a program that would exceed the limitations of Tripwire.

AIDE is not installed by default. Install it with the command:
# yum install aide

Customize /etc/aide.conf to meet your requirements. The default configuration is acceptable for many
environments.

Generate a new database:
# /usr/sbin/aide --init
By default, the database will be written to the file /var/lib/aide/aide.db.new.gz.
The database, as well as the configuration file /etc/aide.conf and the binary /usr/sbin/aide (or hashes
of these files) should be copied and stored in a secure location. Storing these copies or hashes on read-only
media may provide further confidence that they will not be altered.
Install the newly-generated database:
# cp /var/lib/aide/aide.db.new.gz /var/lib/aide/aide.db.gz
Run a manual check:
# /usr/sbin/aide --check
If this check produces any unexpected output, investigate. 

Implement checking with whatever frequency is required by your security policy. A once-daily check may be
suitable for many environments. For example, to implement a daily execution of AIDE at 4:05am, add the
following line to /etc/crontab:
05 4 * * * root /usr/sbin/aide --check

phpBB on CentOS /RedHat /Fedora

THE #1 FREE, OPEN SOURCE BULLETIN BOARD SOFTWARE

phpBB is a free flat-forum bulletin board software solution that can be used to stay in touch with a group of people or can power your entire website. With an extensive database of user-created modifications and styles database containing hundreds of style and image packages to customise your board, you can create a very unique forum in minutes.

Requirements

phpBB3 has a few requirements which must be met before you are able to install and use it.

• A webserver or web hosting account running on any major Operating System with support for PHP
• A SQL database system, one of:
  • MySQL 3.23 or above (MySQLi supported)
  • PostgreSQL 7.3+
  • SQLite 2.8.2+
  • Firebird 2.1+
  • MS SQL Server 2000 or above (directly or via ODBC)
  • Oracle
• PHP 4.3.3+ (>=4.3.3, >4.4.x, >5.x.x, >6.0-dev (compatible)) with support for the database you intend to use.
• getimagesize() function need to be enabled.
• These optional presence of the following modules within PHP will provide access to additional features, but they are not required.
  • zlib Compression support
  • Remote FTP support
  • XML support
  • Imagemagick support
  • GD Support

If your server or hosting account does not meet the requirements above we are afraid phpBB3 is not for you.

#yum install  mysql mysql-server httpd php php-mysql php-gd php-imap php-ldap php-odbc php-pear php-xml php-xmlrpc phpmyadmin

#service httpd start
#service mysqld start
#mysql_secure_installation (set up root password)
#wget http://sourceforge.net/projects/phpbb/files/phpBB%203/phpBB%203.0.7-PL1/phpBB-3.0.7-PL1.zip/download
http://www.mydomain.com/phpBB3/install/

:D