If you need the initial user which you used to login to your Linux system or the time when you login you can do:

whoami

One purpose of this could be the .bashrc to show different Bash Prompts for root to different users:

if [ $(whoami) = "root" ]; then
   PS1='${debian_chroot:+($debian_chroot)}\[\033[41;33m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
else
   PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
fi

Copy and paste at will, they're free!

• German quotation marks: „ “ (Ubuntu-Hotkey: AltGr+v and AltGr+b)
• English quotation marks: “ ”
• En dash: –
• Em dash: —
• Ellipsis: …

Some useful hints for users of Ubuntu Linux

• Your Ubuntu comes with a searchable list of Unicode chars. Go to Accessories / Character map. Ctrl + F searches for a character by name.
• If you want to write all of them (and more) yourself, [configure a compose key](https://makandracards.com/makandra/1030-insert-an...

• Also works on Gnome 2
• Much prettier than Skype notifications
• Better visibility

Promises unified window for all chat conversations, better call quality.

Upgrade seems to work fine. If you installed your old skype from a Ubuntu repository, you need to remove it first using:
sudo apt-get remove skype
Then simply install the .deb from the official page. You won't lose any settings.

If you are using VNC to run Selenium tests, it may be hard to see what's going on since by default there is no list of open windows and Alt+Tab won't work.

Solving that is easy:

1. Install a panel of your choice (like lxpanel) which offers task switching:

   sudo apt-get install lxpanel
   

   (You can't use gnome-panel because it won't start twice -- but lxpanel does a good job)

2. To have that panel appear on VNC screens by default, edit ~/.vnc/xstartup...

uname -m

i686 means 32-bit.

This is one possibility to do this. There are other and maybe even better ways to do this.

1. Generate a key for your encrypted harddisk:

   dd if=/dev/random of=/home/bob/keyfile_sdb1 bs=4096 count=1
   

2. Then add your keyfile to encrypted harddisk: How to change your dm-crypt passphrase (step 3)

3. Create a mountpoint:

   mkdir /mnt/space
   

4. Create a script e.g. in your homedirectory (/home/bob/mount_sdb1.sh):

   #!bin/bash
   
   ...
   

TeamViewer 6 and lower had an issue where they would see a multi-monitor Linux setup as a single wall of pixels. This is fixed in version 7. The guest can now select the currently active screen from the TeamViewer menu.

Sometimes you need to restart the Gnome panel, e.g. when you installed a new Gnome panel widget but the widget list was cached before.

You often don't want to do sign out and back in for this.
Instead, just run:

killall gnome-panel

This will terminate all gnome-panel processes. On my machine (Ubuntu 11.04) the panel then restarted itself after a moment.

If the panel does not automatically come back, press Alt+F2 to bring up the Gnome "run" box and start gnome-panel from there.

SkypeTab-NG (NG stands for Next Generation) is a tool that adds tabs to Skype for Linux. Besides providing a tabbed chat window, the SkypeTab-NG also embeds both the conversation and the main Skype windows in a single window.

When Rack::Bug has been added to your project and your Apache2/Passenger only replies with an Error 500 (Internal Server Error) you won't get any love from both application and Apache logs.

You can start a script/server and try connecting there. It should also fail but you will most likely see this error:

Internal Server Error  
undefined method `new' for "Rack::Bug":String

While the following is (for some reason) working on OSX...

config.middleware.use "Rack::Bug", :secret_key => '...'

...you need to do this so it wor...

Web fonts are awesome. After being restricted to Arial for two decades there is finally a cross-browser way to embed fonts into web pages.

Unfortunately while web fonts look awesome on Linux and MacOS, they look horrible on Windows, a problem that gets worse with smaller font sizes.

The culprit is something called font hinting:

...

When using the screen tool you may be unable to start a screen session but instead encounter an error:

Cannot open your terminal '/dev/pts/0' - please check.

This is because another user (you) initiated the current terminal -- you probably did a sudo su into the user you are now trying to run screen as, right?

There are two ways to resolve this:

• Sign out and properly connect / sign in as the user you wish to use.
• Run script /dev/null to own the shell (more info over at [Server Fault](http://serverfault.com/questions/116775/...

The colors in Rails log files are helpful when watching them but, since they are ANSI color codes like ^[[4;36;1m, can be annoying when you are reading the logs with a tool that does just prints those control characters (like less or vim).

Remove them with sed:

cat staging.log | sed -r "s/\x1B\[([0-9]{1,3}((;[0-9]{1,3})*)?)?[m|K]//g"

This will print the log without colors to your terminal. You can pipe the result into less for example.

To have a file you can vim around with, just write that output into a new file:

ca...

This will reduce the filesize of foo and bar to 0 bytes:

truncate -s0 foo bar

If the files do not exist they will be created.

You can use this to easily truncate your application's log files:

truncate -s0 log/*.log

You can use fold:

fold -sw 60

You can now paste your texts. fold will echo them back, word-wrapped after 60 columns. Exit with Ctrl+C or Ctrl+D.

You can also use files for input and output:

fold -sw 60 input.txt > output.txt

When you drag a file from a Nautilus window into a terminal window, the file's path will be pasted into the terminal. This also works with multiple files.

Whenever Firefox updates, all your Cucumber features that use Selenium break. This is annoying.

In order to remedy this, version 0.5.0 of our geordi gem comes with a script that helps you create an unchanging version of Firefox for your Selenium tests. In particular, this new copy of Firefox will have the following properties:

• It won't update itself with a newer version
• It can co-exist with your regular Firefox installation (which you can update at will)
• It will use a profile separate from the one...

Microsoft provides virtual machine disk images to facilitate website testing in multiple versions of IE, regardless of the host operating system. Unfortunately, setting these virtual machines up without Microsoft's VirtualPC can be extremely difficult. These scripts aim to facilitate that process using VirtualBox on Linux or OS X. With a single command, you can have IE6, IE7, IE8 and IE9 running in separate virtual machines.

Great blog with daily news and HOWTOs for Ubuntu, Linux and Gnome.

DeaDBeeF is one of the better music players for Linux.

You can find installation instructions here.

Note that converting from RGB to CMYK will usually degrade your colors because no exact mapping is possible. Anyway, this Stackoverflow post worked for me:

gs -dSAFER -dBATCH -dNOPAUSE -dNOCACHE -sDEVICE=pdfwrite \
-sColorConversionStrategy=CMYK -dProcessColorModel=/DeviceCMYK \
-sOutputFile=output.pdf input.pdf