increase sudo timeout

February 12, 2017 Leave a comment

Problem
You want to increase the sudo password remember timeout.

Solution
Run “sudo visudo“, then add this line to the end:

Defaults    timestamp_timeout=60

Where 60 means 60 minutes. If you specify -1, then the password is never forgotten (which is not a good idea IMO).

Tip from here.

Categories: bash, linux Tags: ,

[manjaro] let “Super + d” show the desktop

February 9, 2017 Leave a comment

Problem
The “Windows key + d” (aka “Super + d”) minimizes all windows, i.e. it shows you the desktop. It works under Windows, it works under Ubuntu, but for some mysterious reason, under Manjaro (XFCE), it’s “Ctrl + Alt + d” that I’ll never get used to.

How to use the well-known “Super + d” shortcut?

Solution
There must a keyboard shortcut editor for this, but I never find it. So I created a new shortcut that calls a command-line application that minimizes all windows. This way you get the same result. The command-line command for showing the desktop is “wmctrl -k on“. You may have to install the package wmctrl.

Go to the Start menu, start typing “keyboard”, and open the Keyboard application. Go to the “Application Shortcuts” tab and add the “Super + d” shortcut to the command “wmctrl -k on“.

Categories: manjaro Tags: ,

a new range of shortcuts with the Hyper key

February 9, 2017 Leave a comment

On the YouTube channel of gotbletu I found a very nice trick (video). It explains how to replace the Caps Lock with the so-called Hyper key. And why? Because Caps Lock is pretty useless and you cannot use it for shortcuts. But if you tell the system that at the place of Caps Lock there is another key, namely the Hyper key, then you can use a new range of shortcuts.

You can find my .Xmodmap file here. Just put it in your HOME folder and upon the next reboot it’ll be activated automatically. To activate it without a reboot, use the command “xmodmap ~/.Xmodmap“.

Then, under Manjaro (XFCE), go to the Start menu, start typing “keyboard”, and open the Keyboard application. Go to the “Application Shortcuts” tab and add some new shortcuts. This time, when you press Caps Lock, it’ll be recognized as the Hyper key. I added these:

Hyper + g    gedit
Hyper + k    konsole
Hyper + f    file browser (thunar)

Update (20170416)
Under Manjaro I had to create the .Xmodmap file and it is read automatically at each boot. However, under Ubuntu it’s not the case. I tried several methods and here is what worked for me: add “xmodmap ~/.Xmodmap” to the end of your ~/.bashrc file. Now, when you open a terminal, it’ll be activated for sure.

Music video

And if Hyper Hyper, then Scooter, of course:

loop a youtube video

January 28, 2017 Leave a comment

Problem
You find an awesome music video and you want to play it in an infinite loop.

Solution
You need to re-format the youtube URL a bit. Sample:

Input: https://www.youtube.com/watch?v=VIDEO_ID

Output: http://www.youtube.com/v/VIDEO_ID?version=3&loop=1&playlist=VIDEO_ID

Concrete example: input, output.

Tip from here.

Don’t paste blindly to your terminal

January 27, 2017 2 comments

Most of the time when we see a code snippet online to do something, we often blindly copy paste it to the terminal.

Well, the copied text may contain some malicious code. Here is a post about that with a demo.

Categories: bash Tags: , ,

VPN list

January 23, 2017 Leave a comment

Autovpn is a nice and simple project to easily connect to a VPN in a country of your choice.

If you need a VPN list, you can find the necessary URL in its source.

Here is a Python implementation too (link).

Categories: bash Tags: ,

[ml] Visualizing K-Means Clustering

January 22, 2017 Leave a comment

Here is a very nice visualization tool for k-means clustering: https://www.naftaliharris.com/blog/visualizing-k-means-clustering/ .

k-means clustering

k-means clustering