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detect easily if your machine is frozen

October 6, 2014 Leave a comment

Problem
Very rarely my system gets frozen. But is it just my keyboard and mouse that have problems? Or is my whole machine frozen? Or is it just temporary and everything will be normal in a few seconds?

Solution
I have an easy solution to detect if the whole system is frozen. In the top right corner you have a clock, right? Well, add seconds too :) If the seconds are stuck, there is a problem. If they are moving, there is still hope.

clock

Update (20141014)
Yesterday my machine got frozen quite interestingly. I got an email with a youtube link that I wanted to play in Gmail. The machine got frozen, i.e. the mouse/keyboard had no effect and the clock didn’t move BUT the audio of the video was rolling :) I could do nothing but listen to it. At the end I had to restart the machine manually. Lesson learned: even if the clock is stuck, it doesn’t mean that your machine is completely frozen. (I guess this all happened because of Flash).

Categories: ubuntu Tags: ,

[manjaro] Manjaro: a fast, user-friendly, desktop-oriented operating system based on Arch Linux

October 4, 2014 3 comments


Ubuntu has been my primary operating system in the past 7 years. I got to know it quite well. New versions don’t bring too many exciting things, so I was looking for some “adventure” :)

One of my students, DMZ, talked to me about a cool Linux distribution called Manjaro. I’ve never heard about it before but what he said about it made me curious. It’s based on Arch Linux but much easier to set up; it has lots of packages; and it’s very fast. I saw it on his laptop and although it had Xfce graphical environment, it looked quite nice.

I won’t replace Ubuntu with Manjaro on my workstation (not yet, but who knows :)), but Manjaro is a good choice for an older laptop where Ubuntu would be slow. Also, if you need a virtualboxed Linux (for trying out something in a sandbox for instance), Manjaro is an excellent choice: it can be installed quickly, and it boots up very fast.

Well, let’s try it! I put it in Virtualbox and my first impressions are really positive. Here I collect some notes.

pacman: transaction not initialized
I think it’s a bug in Manjaro 0.8.10. The Update Manager cannot run correctly right after the installation. Here is the fix:

sudo pacman-mirrors -g
sudo pacman -Syy
sudo pacman -Syu
sudo pacman -Syu

After this you can do a package update with the Update Manager. This tip is from here.

Increase icon size
If you find the desktop icons small, then right click on the desktop and discover the Desktop Settings. You can also set that you need to click on an icon just once to open it.

Launchers
Right click on the desktop and add some launcher icons to the desktop (e.g. Firefox, Terminal, etc.). From the desktop you can also drag and drop icons to the bottom panel.

Install a newer kernel
In the bottom left corner click on the “Start” button. Then Settings -> Manjaro Settings Manager -> Kernel. You can select an LTS kernel, or you can select the newest one.

Install a new package
The package manager of Manjaro (and Arch) is called pacman. You can install a new package with it like this (example):

sudo pacman -S vim mc

Show running apps on the bottom panel
The bottom panel showed the running apps but somehow I managed to make it disappear :( Here is how to get it back: right click on the bottom panel, Panel -> Add New Items…, and add the “Window Buttons” plugin.

If you want to change the order of plugins on the bottom panel: right click on the panel, Panel -> Panel Preferences…

Create a shared folder between the Virtualbox host and guest
Follow the instructions here.

Categories: manjaro Tags:

Firefox is started automatically but it looks corrupted

September 28, 2014 Leave a comment

Problem
On my home desktop I have autologin enabled, i.e. I don’t need to log in manually. Since I always need a terminal and a browser, “konsole” and “firefox” are started automatically. So I just switch on my machine and when I come back 5 minutes later, I’m ready to work.

However, sometimes Firefox doesn’t start normally. It looks strange: some colors are replaced with a different one, fonts are different, tooltips on tabs are plain black (text in tooltips is not visible), etc. If I restart Firefox, it becomes OK. I’m not sure what causes this problem, but my guess is that Firefox is started too quickly. I think it would require some libraries that are not yet loaded when Firefox is started. Then these pieces of software are loaded, that’s why Firefox gets OK after a restart.

Solution
The solution is simple. Don’t start Firefox immediately after the login. Wait some time until everything else is loaded, and start it after. Of course, we still want to start Firefox automatically, not manually. So we need a simple script:

#!/usr/bin/env bash

# /home/jabba/bin/start_firefox.sh
sleep 60    # Wait 60 seconds. You can play with this value.
/usr/bin/firefox &

Then in the Startup Applications, remove “firefox” and add this script instead. Provide the absolute path of the script. Make sure it’s executable. Here is a screenshot of the applications that are started automatically on my machine:

start_firefox

Categories: firefox, ubuntu

Git push requires username and password

September 15, 2014 Leave a comment

Problem
You want to push a new project to github, but it asks for your username and password each time.

Solution
I found the solution here. Here I copy Davide‘s answer (reformulated a bit):

First, check the remote repository:

git remote -v

which will respond something like

origin  https://yourname@github.com/yourname/yourrepo.git (fetch)
origin  https://yourname@github.com/yourname/yourrepo.git (push)

Execute the following command:

git remote set-url origin git@github.com:yourname/yourrepo.git

Notice that you need to do some transformations: “https://yourname@” is replaced with “git@“, and “/yourname” becomes “:yourname“.

Now “git push” should work fine.

Categories: Uncategorized Tags: ,

Launch gedit in the background

September 11, 2014 1 comment

Problem
Sometimes I use gedit but it is launched in the foreground, blocking my terminal. There are two ways to put it in the background: (1) Press CTRL+Z in the terminal, then send the job to the background with the command bg, or (2) launch gedit directly in the background with the “&” sign.

Neither of them is convenient. I often forget about it and I always end up in a blocked terminal. I just simply want to write “gedit” or “gedit ehh.txt“, and I want it to start in the background.

Solution
Create a script called “gedit” in your $HOME/bin directory with the following content:

/usr/bin/gedit "$@" &

Make it executable and make sure the directory $HOME/bin is in your PATH.

Categories: bash, ubuntu Tags: ,

block a person’s calls and SMS messages on Android

September 6, 2014 Leave a comment

blocker
Problem
You don’t want to get the calls and SMS messages of a given person. However, you want to see his/her calls and messages in a log.

Solution
I tried Calls Blacklist and it works well for me.

Categories: android Tags:

Windows 8.1 with Linux

September 4, 2014 Leave a comment

I got a new laptop at my workplace, a Toshiba Satellite C55. I decided to put Windows 8.1 and Ubuntu 14.04 LTS on it.

Installation
I had a Windows 8.1 ISO but I didn’t want to burn it on a DVD. Instead, I put it on a USB stick. I found an excellent tool called Rufus that allows you to create a bootable USB stick from an ISO file. Here is a youtube video tutorial too.

When Windows 8.1 was installed, the next step was to install Ubuntu. Restarting Windows is tricky if you want to change the boot order: hold down the SHIFT key and select reboot while pressing the SHIFT. Upon reboot I had to press F12 to get to the boot order menu.

Installation of Ubuntu went flawlessly.

NTFS partitions cannot be mounted
Once I had a strange problem. Ubuntu started to complain that it cannot mount the Windows partitions. It turned out that Windows was hibernated and thus the NTFS paprtitions cannot be mounted in read/write mode. But why is it hibernated when I restarted Windows?

Well, another “cool feature” of Windows 8.1 is that you can power it off / restart it in two different ways! Option 1: right click on the Windows button in the bottom left corner and select halt / restart. This will do some hibernation, thus the next boot will be faster. Option 2: move the mouse to the bottom right corner, wait for the tiles to show up and halt / restart the machine there. It is a normal power off / reboot without any hidden hibernation.

So, if you use Linux with Windows 8.1 in dual boot, you’d better stop / restart Windows using Option 2 (on the right side).

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