IRC - Could not resolve your hostname: Domain name not found; using your IP address instead

Quite an annoying message when you're trying to connect to an irc channel to get some help. You stay connected for a while, and then get kicked off the channel with the message above.

When I'm in a real, real hurry and have no wish to try resolve the issue, I just go to the web-based IRC client - http://mibbit.com/ and connect to the channel I need. It works fine, I get the help I need.

Could not resolve your hostname: Domain name not found; using your IP address instead - still don't know for sure how to bypass this. Also because in some clients like Konversation or XChat the error doesn't prevent from using the channel, while in others it results in getting disconnected.

Flash videos colors on Linux / Ubuntu

If you've found out that when watching flash videos on Youtube or on other websites, the colors are shown blue on your system, don't worry, do the following:

Right click on the flash video -> Settings -> Uncheck Enable hardware acceleration -> Refresh the page.

This should solve the issue, and the video should show the correct colors.

Skype on Kubuntu 12.04 - 13.04 / 64 bit - ugly mouse theme

When you install skype (which is a 32bit software) on a 64 bit Kubuntu 12.04 system from the official Ubuntu repositories, you find out that when you focus the skype window, the mouse theme changes for a classic KDE mouse theme.

That might be fine if you're using that mouse theme system wide. However, if you're using the default nice-looking KDE Oxygen mouse theme, you most probably find the cursor style in focused skype utterly ugly.

To solve this, remove skype from the official Ubuntu repos ('sudo apt-get remove style', if you have it installed, of course), access the official skype website, and get a "64bit" skype version for your Kubuntu 12.04 from there -  http://www.skype.com/intl/en/get-skype/on-your-computer/linux/. By the way, the version on the skype website is the most recent, and the one in the Ubuntu repos is not.

Install the downloaded binary file, and you're done - skype is going to use your default mouse theme. That's easiest way.


Update

Since the above-described way no longer results in a successful resolution of the cursor theme problem at least for Kubuntu 13.04, so here is how to actually make Skype use the default on Kubuntu 64bit:

sudo apt-get install ia32-libs

So what was the problem - Skype needs this dependency -  libxcursor. Its 64bit version comes preinstalled, but being a 32bit app, Skype needs a 32bit version of the dependency.
Why install the package ia32-libs (which pulls in quite much stuff) and not just libxcursor 32 bit -- because for Ubuntu the lib is packaged in a larger package - ia32-libs. So you'll have to install the whole package. Anyway, that will successfully resolve the issue with the skype cursor theme.

How to install mod_rewrite on Ubuntu 12.04

After you've installed the Apache web-server and php on Ubuntu, you find out there is no mod_rewrite installed and available.

Here is how to install mod_rewrite on Ubuntu 12.04 (actually, this is actual for at least Apache on Ubuntu 6.04).
Launch a terminal and run:

sudo a2enmod rewrite


Restart apache. Done.

Debian Administrator's Manual

Recently I've come across this very nice Debian manual describing the famous open-source linux-based distribution.

The handbook was written by 2 members of the Debian project Raphaël Hertzog and Roland Mas which is a good sign generally as the guys must know pretty well what they're writing about. The book is aimed to cover all the aspects of Debian, including how the distro is build along with the practical aspects of administering a Debian based system. It is also a fresh book, published on May 2012 (not in 2001 for example).

In short, if you want to learn about Debian from within, the book is for you. If you plan to administer Debian based desktops or web-servers, the book is for you as it covers a lot of  topics a future system administrator should know:
- how to set up the Apache webserver on Debian,
- how to secure a web-server on Debian,
- virtualization on Debian (KVM/Xen/LXC),
- automatic installations, etc.

You can get an electronic version of the book from here for free, also check their website for ways to obtain a paper-copy if you prefer books in that format.

Ubuntu 12.04 / 12.10 - rcconf needs dialog or whiptail

RCCONF is a TUI (text user interface) utility that lets you configure the services and daemons that are launched at system start-up.

When you install it on Ubuntu 12.04 / 12.10 and then launch, it returns the following error:

"rcconf needs dialog or whiptail"

Dialog and whiptail are utilities to display user-friendly dialog boxes from shell scripts. Despite the fact that whiptail comes preinstalled with the system, rcconf doesn't run.

Solution 1:

install dialog:

sudo apt-get install dialog

Now launch a terminal, and run rcconf.

Solution 2:

Whiptail is already there, but not in the folder the apps try to launch it from (see the comment by Viajemotu below). All you need to do is to create a symlink to the app in the /usr/bin directory. To do so, execute:

$ sudo ln -s /bin/whiptail /usr/bin/whiptail

After this, run rcconf.

Linux Mint IRC channel

Here is how to connect to the Linux Mint IRC channel:

Server: irc.spotchat.org
Channel: linuxmint-help
linuxmint-chat