How to download YouTube video on Ubuntu

You can download YouTube video with youtube-dl.

Install youtube-dl

sudo apt-get install youtube-dl

Download the video

youtube-dl http://the-youtube-video-uri

Convert into MPEG format

ffmpeg -i source.flv output.mpg

How to install Java on Ubuntu 9.04

To install Java support on Ubuntu, run this command in a Terminal:

sudo apt-get install sun-java6-jdk sun-java6-jre sun-java6-plugin

You can also click here to test whether the JVM is working fine in your browser.

How to enable Apache public_html for user on Ubuntu

Suppose that you want each user to have their own public_html in their home directory.

For example, user with username ahmad, can have his own Web site at

http://localhost/~ahmad

Enable mod_userdir

To achieve that, first, what you need to do is to enable mod_userdir, which is installed by default with Apache2.

sudo a2enmod userdir

Create public_html directory

Second, the user need to create public_html directory in their home directory.

mkdir public_html

Restart Apache

Finall, you should restart Apache.

sudo /etc/init.d/apache2 restart

Convert CHM to PDF on Ubuntu

By default, you cannot view CHM file in Ubuntu. To view the CHM file, you can use GnoCHM. However, I found that GnoCHM is not so stable and crash a lot. Hence, another option is to convert it to PDF. What you need is the chm2pdf and python-beautifulsoup packages.

Install the packages

sudo apt-get install chm2pdf python-beautifulsoup

Convert the CHM file to PDF

chm2pdf --webpage --beautifulsoup filename.chm

You can even change colour, font, and margin of the generated PDF file. For more information on how to do so, please invoke

man chm2pdf

command on the terminal.

Determine CPU temperature on Ubuntu

Most PCs these days use ACPI. The ACPI shows information such as battery status or thermal information. Hence, to determine the CPU temperature on Ubuntu, you can use the acpi package.

Install the acpi package

sudo apt-get install acpi

Display the temperature

acpi options:

-b, --battery battery information
-B, --without-battery suppress battery information
-i, --capacity show battery capacity information if available
-a, --ac-adapter ac adapter information
-A, --without-ac-adapter suppress ac-adapter information
-t, --thermal thermal information
-T, --without-thermal suppress thermal information
-c, --cooling cooling information
-C, --without-cooling suppress cooling information
-V, --everything show every device, overrides above options
-s, --show-empty show non-operational devices
-S, --hide-empty hide non-operational devices
-f, --fahrenheit use fahrenheit as the temperature unit
-k, --kelvin use kelvin as the temperature unit

For example, to display information for every device, use the -V option.

$ acpi -V
Battery 0: Full, 100%
Battery 0: design capacity 7800 mAh, last full capacity 7791 mAh = 99%
AC Adapter 0: on-line
Thermal 0: ok, 36.5 degrees C
Cooling 0: LCD 0 of 7
Cooling 1: Processor 0 of 10
Cooling 2: Processor 0 of 10

View CHM file on Ubuntu

Microsoft Compiled HTML Help (CHM) is a common format for e-book and online documentation.

To view CHM file in Ubuntu, you need to have a CHM viewer installed. GnoCHM is one of the CHM file viewer, designed to integrate nicely with Gnome, using PyCHM.

GnoCHM CHM Viewer

GnoCHM can be installed by pasting the following command in the terminal.

sudo apt-get install gnochm

The shortcut will appear in Applications > Accessories menu as "CHM Viewer".

Access GnoCHM from the menu

This article discuss a simple way to view CHM file. If you know a better CHM viewer other than GnoCHM, please leave a comment.

Solar eclipse

Date: July 22, 2009
Time: 0930 GMT +8
Location: Dewan Kuliah 5, UiTM Perlis, Arau, Malaysia.
Photo courtesy of Syed Mohd Hijan Syed Hamzah.