Linux Package Manager Cheat Sheet Reference Chart

Linux comes in many flavors or distros, and each distro handles software installation differently from one another. Most GNU/Linux distro uses a package management system to manage software updates/instalation/removal in order to help users administer their Linux systems.

However, many of these package management system has different interface and commands, as such users from Ubuntu (or Debian based) might only be familiar with ‘apt’ or dpkg while Fedora (Red Hat based) users might only familiar with yum and rpm, which may create confusion when users from either distro were to exchange environments.

Luckily, somebody was kind enough to provide these users with Linux Package Manager Cheat Sheet which act as a reference point whenever a user had to switch to another distro which uses package management that are not familiar with them.

The package management software listed are for: apt,dpkg,yum, rpm, pkg* (slackware based) and AIX-based lsl**.

[ Source ]

How to optimize MySQL tables automatically using cron

Busy websites which has a lot of insert/delete transactions may introduce fragmentation in MySQL tables. Fortunately, users and optimize mysql tables with ‘OPTIMIZE TABLE’ command, but how to execute it automatically?

Here’s how:
The mysql-client package in Ubuntu installation comes with a tool called mysqlcheck which is handy for optimizing table in mysql. This command can be executed from bash and can be executed using cron.

to do that, just run this command.

[bash]
cron -e

#in the crontab file– add this line
59 23 * * * /usr/bin/mysqlcheck -o -v -u <mysql username> -h localhost <database_name> -p <password>
[/bash]

This will tell cron to execute mysqlcheck and optimize mysql table of the specified database exactly on 11:59pm, every day. You can change the setting to suit your need.

How to change hostname in Ubuntu server

Here’s how you can change hostname in Ubuntu server

1. Edit /etc/hostname, and change the hostname
2. Edit /etc/hosts file, and add the hostname to 127.0.0.1, or to any local machine ip
3. run, “sudo server hostname stop”, and “sudo server hostname start”

How to Hide Apache2 and PHP version without using mod_security in Ubuntu Linux

Although security by obscurity is not the best policy to protect your IS assets, but it is still useful to thwarts simple network scanner or newbie crackers.

Note: This tip is written for Ubuntu Linux, the steps is similar to other GNU/Linux distro, albeit with a slight variant.

Hiding Apache2 version
Edit /etc/apache2/apache2.conf

Add these lines at the end of the file:
ServerSignature Off
ServerTokens Prod

Restart Apache2
[bash]
sudo /etc/init.d/apache2 restart
[/bash]

Hiding PHP version
Edit /etc/php5/apache2/php.ini file

Find these lines, and switch it off:
expose_php = Off
display_errors = Off

Additionally you may disable certain ‘risky’ functions in php by editing the disable_functions line:
disable_functions = phpinfo, system,show_source,

Finally, you may restart Apache2 web server.
[bash]
sudo /etc/init.d/apache2 restart
[/bash]

PPSPPA (Sisa Pepejal) goverment agency uses Ubuntu in its office branches

PPSPPA or Perbandanan Pengurusan Sisa Pepejal dan Pembersihan Awam is a government agency in Malaysia that uses Ubuntu in its offices. PPSPPA has branches in every state in the Peninsular, including the HQ and training center in Putrajaya, all of it runs Ubuntu 10.04 LTS operating system.

PPSPPA Logo Sisa Pepejal

As such, PPSPPA only uses hardware which runs in Ubuntu, including printers, scanners and drawing tablets. Which is a good sign for vendors to start releasing their hardware drivers for open source operating systems.

Hopefully other government agency would follow suit and use free and open source operating system instead the one that requires millions RM of site license. It is not the license that concerns us, but it is the grip of monopoly of a single corporation has over governments and economy that is most concerning.