solved!

Opening skype chat links in a wrong browser

2015-06-03T13:15:00.003+03:00

Problem:
Here's the thing. I have Firefox as my default browser. But every time I click a link in Skype chat it opens Chromium.

Solution:
Install extra/xdg-utils (in Archlinux) or whatever package has xdg-mime binary. This command creates and modifies intries in ~/.config/mimeapps.list
Then run
$ xdg-mime default firefox.desktop text/html
$ xdg-mime default firefox.desktop x-scheme-handler/http
$ xdg-mime default firefox.desktop x-scheme-handler/https

You can substitute the *desktop file to the browser of choice.
This also works for other use cases where you need to change the default application for a file type.

back to blogging

2015-04-22T10:22:00.001+03:00

Wow, just noticed it's been two years since the last post. That's a lot of time, since then I've stopped using ubuntu in favour of Arch linux.
Why?
I love the idea of a rolling release, when you have the latest software all the time without the need to reinstall the OS (or upgrade, fail, and then reinstall).
I picked arch and am happy since.

control linux sound from the command line

2013-04-22T07:28:00.001+03:00

Normally a full desktop environment has all the tools to handle the sound. Most likely the laptop multimedia keys are already working fine - mute/increase/decrease volume etc.
But when something is not working, or if you're using a less user-friendly environment /window manager that has no out of the box multimedia keys support you need to do some setup on your own.
This is how you can handle the multimedia keys in i3wm/awesome wm/openbox etc.
The easiest thing is to bind the commands that do the stuff to the keys you want.
Therefore, you need to know the commands that do the stuff :)
In Ubuntu there's 2 ways: use alsa-utils or pulseaudio-utils. So install the corresponding package to be able to use their tools.

Alsa

Toggle mute:
amixer -q -D pulse set Master 1+ toggle

Volume up:
amixer -q set Master 2+ unmute

Volume down:
amixer -q set Master 2- unmute

Pulseaudio

Toggle mute:
Note that this works for sink 1. Use pactl list short sinks to list yours and adjust the command.
pactl set-sink-mute 1 $((pactl list sinks | grep -q Mute:.yes && echo 0) || echo 1)

Volume up:
pactl set-sink-volume 1 +5%

Volume down:
pactl set-sink-volume 1 -- -5%

Now all you have to do is to use whatever method your WM has to bind the keys. You may want to use xbindkeys utility to have a WM-neutral keybindings. This is useful if you switch the WMs often.

asound master toggle doesn't unmute

2013-04-18T07:32:00.001+03:00

People whose multimedia keyboard keys are not working by default (or users of lightweight WM like awesome/i3 etc) set up the keys themselves.
It used to be a well known solution to use amixer to handle sound up/down/mute keys. For example see gentoo wiki.
But in Ubuntu the command
amixer -q set Master toggle
works in one direction - it mutes, but doesn't unmute.
To be short - there's a bug filed, there's a script somewhere posted as a workaround, and there's a one-liner workaround I've posted in the bug comment.
amixer -q -D pulse set Master 1+ toggle
Don't forget to vote for the bug!

No sound is played during incoming skype call on ubuntu

2013-04-12T12:15:00.001+03:00

I've had this multiple times and keep forgetting how to fix it.
Problem:
During the incoming call skype doesn't play the incoming sound, but just displays the notification window.
If you check the settings it seems allright.
The solution:
go to Sound->Preferences->Sound Effects tab and increase the volume there.

split mp3 or extract audio from video

2012-12-15T18:55:00.003+02:00

Split your audio or extract parts from it

Sometimes you want to split an audio file into pieces, e.g. split a large audiobook into smaller parts.
This could be useful since sometimes the input audio is read incorrectly by players. My phone's player shows that the audio length is 58mins, while the actual length is 90mins. This won't let me rewind the media.
Or you might want to cut out some parts of the media - parts with silence, noise etc.
If you only have one file - install the audacity and split the file or extract the parts the way you want. Use this as an example guide.

For multiple files you might want to use some command line tool and have the same actions applied to all of them.
Good tool for this is avconv from libav-tools. This packet is already installed on my system, install it manually if needed.
The command you need is:

avconv -i "$yourfile" -t $part_duration -ss $skip_time -acodec copy -y "$output_file"

-i - your input file
-t - duration of the part you extract. Can be specified in seconds or as hh:mm:ss
-ss - how much time should be skipped from the beginning of the input audio
-y - the destination file for the output

A simple script can do the batch processing - split all the input audio files 30min long. Assume the max length of input is 9000 seconds

#!/bin/bash
#split audio file, output the same codec as input

#time in seconds - the duration of the parts
x=1800
for i in "$@"
do
    sum=0
    while test $sum -lt 9000
    do
        ext="${i: -3}"
        fname="$i".$sum.$ext
        avconv -i "$i" -t $x -ss $sum -acodec copy -y "$fname"
        sum=$((sum+x))
        size=$(stat -c%s "$fname")
        #if the output is small->remove (usually when the input has ended on earlier iterations)
        if test $size -lt 3000
        then rm "$fname"
        fi
    done
done

Extract audio from video

avconv can do this as well.Add the -nv flag to disable the video rendering.

This example extracts the original audio, I suggest to do the recoding (with avconv) in the second step, since it produces strange results if you attempt all at once.
#extract the original track
% avconv -i video.mp4 -t 10 -ss 0 -acodec copy -vn -y sound.aac
#recode to ogg
% avconv -i sound.aac -acodec libvorbis -y sound.ogg
For single files use the GUI way - install avidemux.

It allows you to select the region and extract the sound from it.

Laptop brightness increases/decreases in two steps

2012-10-31T06:59:00.001+02:00

On (at least) lenovo laptops the brightness control increases/decreases brightness in two steps. This doesn't allow for a fine control over the brightness.
There is a bug report on this, but the quick workaround is to run

% echo N |sudo tee /sys/module/video/parameters/brightness_switch_enabled

The setting is not remembered between boots - add it to the autorun or you'll have to rerun it.
Still for me it only affects the decrease, increasing is still in step of 2.

Ubuntu 12.04: new DNS and VPN issues

2012-05-23T08:10:00.000+03:00

In Ubuntu 12.04 there's 2 major changes with regards to DNS resolving:
1. resolvconf is now used by default
2. a local resolver is now hardcoded into network manager and is used by default

This means that you'll see nameserver 127.0.0.1 in your /etc/resolv.conf at all
times, while the real DNS config is managed by dnsmasq started by NetworkManager.
You can see the current DNS config in /run/nm-dns-dnsmasq.conf
There are numerous issues that this approach introduces. More info on the change and possible issues/solutions are here - http://www.stgraber.org/2012/02/24/dns-in-ubuntu-12-04/

My issue was that one of the VPN providers wasn't properly sending the search domain, so I couldn't access the servers by names on this network.

The easies solution is to add the DNS and search domains manually

Change dash lens hotkey

2012-05-15T15:45:00.002+03:00

Although CCSM offers a way to change some of the Unity hotkeys, some are not there.
You cannot change the unity dash lenses hotkeys like Super+M or Super+F for music and files lenses.
To disable or change the hotkeys you'll need to edit the lens files.
Open nautilus and navigate to the lens files.

$ gksudo nautilus /usr/share/unity/lenses/

Open the corresponding lens folder, and edit the *.lens file.
There is a Shortcut=<> entry. Change the letter or remove it to disable the hotkey.
If you want to disable the lens add the ShowEntry=false entry.
To apply the changes run
$ setsid unity
Works in Ubuntu 12.04

ubuntu pgp key errors

2012-01-30T06:36:00.003+02:00

Q: I get error like
GPG error: http://archive.ubuntu.com oneiric Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>
A:
try the following

sudo apt-key del 40976EAF437D05B5

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 40976EAF437D05B5

Then run apt-get update again. If you still get the errors, you need to remove the old files manually.

sudo apt-get clean
cd /var/lib/apt
sudo mv lists lists.old
sudo mkdir -p lists/partial
sudo apt-get clean
sudo apt-get update

install xfce on a base server system

2011-12-26T12:42:00.000+02:00

So, after installing xubuntu I wanted to check plain xfce.
Is xfce + base ubuntu the same as xubuntu?
The plan was to take base ubuntu system, without the desktop (cli only) and install xfce on top. Then compare it to xubuntu.
I noticed that xubuntu has some gnome apps installed, so I wondered if I could do without them on a fresh install.
Here's the steps to add gui to your server:

install X - #apt-get install xorg
you should be able to start x manually with startx now.
install display manager. I used lightdm.
I immediately got an X server after that, since by default unity-greeter is installed along. Had to install lightdm-gtk-greeter, but this wasn't sufficient. Had to find the lightdm config where it references the unity-greeter and change it manually.
So, to avoid problems, install lightdm by: #apt-get install lightdm-gtk-greeter
Now I wanted proper video drivers. So I installed ubuntu's driver utility and activated the nVidia and Broadcomm STA.
#apt-get install jockey-gtk then run jockey-gtk and activate the drivers.
Wireless. Pick either wicd or network-manager. Usual install.
Sound. Sound on linux is a mess. I had to remove pulseaudio once, so I installed just alsa and gstreamer.
#apt-get install gstreamer0.10-alsa
Now install the desktop environment or window manager. I installed awesome WM and xfce. Awesome was for experimenting with. Pick what you want.
#apt-get install awesome xfce4

Although it should be fine now, I had some issues.

I couldn't do some of the actions like connect to the wifi from Network Manager, mount without sudo. Had to install policykit desktop stuff:
#apt-get install policykit-desktop-privileges
The look of the xfce desktop was not pretty. Had to install some extras to make it look like the xubuntu:
#apt-get install dmz-cursor-theme xubuntu-icon-theme elementary-icon-theme
Internal microphone not working, external not working in some apps. Had to play with snd_hda_intel. For my dell latitude d630 the model should be dell-m42, but really both internal and external mics worked only with model=5stack
There were no notifications shown, you know, the baloons that show system events. You need to install xfce4-notifyd
wireless was working fine with Wicd, but Wicd appeared to be slower than NM to pick the hotspot, also I lacked some extra config like mtu. With NM the PC was disconnecting randomly, refusing to connect aftewards. Reinstalling the NM didn't help. Then it refused to connect to secure networks, showing in the log stuff like
NetworkManager[1639]: <info> (wlan0): device state change: config -> need-auth (reason 'none') [50 60 0]
NetworkManager[5477]: <warn> No agents were available for this request.
<info> (wlan0): device state change: need-auth -> failed (reason 'no-secrets') [60 120 7]

The reason was that it never showed the key input dialog. And the cause was that it needed gnome-keyring. After I've installed it all was working fine.
After all, I guess I understand now why xubuntu has these gnome apps shipped :)

root/unroot android under ubuntu with superoneclick

2011-12-13T08:39:00.000+02:00

Short guide on how to root an android phone under ubuntu 11.10
Actors: Superoneclick, Samsung Galaxy i5800, xubuntu 11.10

I'm posting direct links to downloads, if they're not valid - just google for it.
I'm not explaining the basics of package installations. Google for it or read my posts.
The process might differ slightly on other versions of Superoneclick or ubuntu.

1. You need to have these installed: lib32ncurses5 lib32stdc++6 mono mono-winforms.
On ubuntu 11.10 I have these:

$ sudo apt-get install lib32ncurses5 lib32stdc++6
$ sudo apt-get install mono-runtime libmono-corlib2.0-cil libmono-winforms2.0-cil

2. You'll need the Superoneclick app that does the actual root/unroot. I used ver. 2.2 from here. Extract it somewhere.

3. I have android SDK, but you can use the adblinux inside the superoneclick's ADB dir.
Enable USB debugging in your phone (On the device, go to Settings > Applications > Development and enable USB debugging), and plug your phone in the USB cable.
Run it to check connection:

super1c-2.2/ADB$ chmod +x adblinux

super1c-2.2/ADB$ ./adblinux devices
List of devices attached
???????????? no permissions

If you have the same message, follow me. Otherwise skip to running Superoneclick.

4. As described here, we add a udev rules file that contains a USB configuration for your phone. In short:
As a root create the following file: /etc/udev/rules.d/51-android.rules with the content:

SUBSYSTEM=="usb", ATTR{idVendor}=="<YOUR VENDOR>", MODE="0666", GROUP="YOUR_GROUP"

Chande the YOUR_GROUP and YOUR VENDOR. Run:

$ id
uid=1000(akm) gid=1000(akm) groups=1000(akm),4(adm),20(dialout),24(cdrom),46(plugdev),116(lpadmin), 118(admin),124(sambashare)

$ lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 003: ID 03f0:231d Hewlett-Packard
Bus 001 Device 004: ID 138a:0007 Validity Sensors, Inc. VFS451 Fingeprint Reader
Bus 001 Device 005: ID 04f2:b15e Chicony Electronics Co., Ltd
Bus 002 Device 004: ID 046d:c050 Logitech, Inc. RX 250 Optical Mouse
Bus 002 Device 005: ID 04e8:681c Samsung Electronics Co., Ltd Galaxy Portal/Spica Android Phone

So group is akm, and vendor is 04e8.
Unplug and plug again the phone and check. You might need to restart udev:

$ sudo service udev restart
$ ./adblinux devices
List of devices attached
6892da31efa7 device

5. Now finally the rooting. To run Superoneclick you need to have mono installed.
NOTE: I'm not a mono guru. I had mono installed along with keepass2, and I got libmono-corlib4.0-cil installed. You need to install libmono-corlib2.0-cil if you have this.(see step 1).

super1c-2.2/ $ mono SuperOneClick.exe

Turn off the phone, and plug it into the cable. Click "Root button" and turn the phone on.

vim pro tips

2011-12-12T15:28:00.000+02:00

Q: how to write file a that requires sudo, but the file is opened without it?
A: Use
:w !sudo tee %
Then enter the sudo password

Q: change line ending <EOL> in vim
A: Use
:set ff=STYLE
Where STYLE is one of unix/dos/mac

Q: change file encoding. Change character encoding in vim
A: just to change: :set enc=utf-8
To open a file with an encoding:
:e ++enc=koi8-r russian.txt
To write a file in encoding:
:w ++enc=koi8-r russian.txt

Q: change case of a letter. Change case of a selection
A: ~ - change case for letter (also for selection). Selection: u (lowercase), U(uppercase).
gu{motion} or gU{motion} - lower or upper case to motion (w,b,$ etc)
guu or gUU - lower or upper case line

Q: learn what a shortcut does (for example ctrl-w)
A: :help ctrl-w

Q: Working with windows in vim
A: Windows are viewports to a buffer, simpler put - views of a file.
:he windows for more info. All the shortcuts start from Ctrl-w, easy.
Windows can be split (ctrl-w s -horizontal, ctrl-w v - vertical), another buffer can be opened into the split (:sp, :vs for horizontal and vertical split)
ctrl-w w - Cycle between windows
ctrl-w =, ctrl-w |, ctrl-w _ - equal windows in size, maximize current horizontally, maximize current vertically

Q: How to reformat code, for example html/xml
A: First, you need to have filetype indent option set to on in your ~/.vimrc:

filetype indent on

Then select the lines and press = or type gg=G
If vim didn't recognize the file type properly, e.g. when you're formatting a code snippet, just tell vim what type it is:
:set filetype=xml

Q: copy to system clipboard
A: system clipboard's name is +, therefore to copy:
"+y and to paste "+p
NOTE: vim has to be compiled with +xterm_clipboard option (run vim --version to see it's compiled options), which is true for GUI vim. Terminal vim on Ubuntu 11.10 doesn't have this option.

Q: Folding
A: to make folding work automatically, you need the foldingmethod (fdm) set to smth other than manual. I use :set fdm=indent .
zc/zo/za - for the current cursor position close/open/toggle folding on current level
zC/zO/zA - for the current cursor position close/open/toggle folding on all levels
zr/zm - reduce/increase the folding by 1 level thru the whole buffer.
zR/zM - reduce/increase the folding on all levels thru the whole buffer.

Q: comment/uncomment lines
A: Use visual block for it:
ctrl-v select the first chars on the lines you want to comment, press I (uppercase i, stands for insert at the line start), insert the comment char(s) followed by <Esc>.
To uncomment select the comments in the block selection, press d. Or use replace :s/^#/

replace ubuntu with xubuntu

2011-11-30T18:13:00.001+02:00

Also see installing an xfce in base ubuntu.
Following Linus Torvalds, a lot of people are trying XFCE or other desktops instead of Gnome 3. Well, why not give it a try.

Your options:

fresh install. A fresh install is always better imho, since I'm a kind of purist and don't want to have trash/leftovers. And I have a separate partition for /home :)

But even if you have /home on a single partition with /, a new installation will not mess with your /home, provided you don't choose "format the partition".
install along with Gnome
But if you just want to try, you can install it along with Gnome $ sudo apt-get install xubuntu-desktop You can later remove the ubuntu-desktop (Gnome) and leave only XFCE.

The impressions: Xubuntu is fast and lightweight. The default apps are great and I don't miss a single gnome one.
Xubuntu Pros:

Recommend for minimalists, people with older PC's (for very old use Lubuntu). I'd recommend to have minimum 512Mb RAM for Xubuntu, it was impossible to use it on a 256Mb.
Much more configurable than ubuntu, much like KDE. And this configuration is much better organized than in KDE.

Xubuntu Cons: it still is not a pure XFCE, Xubuntu has some gnome stuff like gnome-keyring shipped. Some stuff needs workarounds, like buggy keyboard switching applet.

Upon install you have 2 panels: top and bottom, just like in Gnome2. But I like to keep just one vertical to save screen space.

Next step: lightweight apps. Try some from there.

I've decided not to have a single gnome app installed.
Here's my software recommendations.

File manager - Thunar. It is great, looking just like Nautilus, same functionality (no tabs though)

Terminal emulator - default (xfce4-terminal) or tilda (from repositories). Both are configurable, but I like tilda, since it hides/shows itself on a hotkey, available on any virtual desktop I'm currently in. If you use terminal frequently and switch desktops - give it a try.

Browser - firefox or chromium. The latter has less dependencies and can be easily installed without pulling any extra libs.

Video player - vlc and mplayer. Both are great, work out of the box without making you install the codecs manually.

Music player - audacious. Very good one, simple, shortcuts for everything, similar to older versions of winamp (when it was just a music player).

Text editor - ~~SciTE~~. Geany. The default Mousepad/Leafpad are too minimal for me.SciTE is too source code oriented. It won't even show txt files in the open dialog by default, filtering only source code extensions. Geany has good source code editing features - syntax highlight, foldings along with other general purpose features. Very low memory consumption, same as gvim.

Application launcher - kupfer. Just try it, you'll never need any shortcuts/launchers. This is a very lightweight alternative to gnome-do.

Application launcher (CLI-like) - the default Alt-F2 xfce runner is ok, but it lacks tab completion. I've replaced it with gmrun.

Clipboard manager - clipman. Install separately or along with xfce4-goodies.Then add to a panel.

Keyboard layout switcher - for now I use a hardcoded layout in /etc/default/keyboard . There's a panel xfce4-xkb-plugin , but it just lets you choose a single hotkey, while I like to have several alternatives, as well as an option to light LED for alternative layouts, remap caps lock to control etc.

More to come..

git revert for svn users

2011-11-27T21:57:00.001+02:00

If you're not familiar with git terminology I suggest some further reading.
Quick terms:

Working directory - where you work and change files.
Index/stage/staging area - where you put the files you want to commit.
Repository - where you commit the changes to.

SVN doesn't have this intermediate Staging area.

Fixing errors, reverting
The action depends on where the error is.

Q: How can I undo the change/remove file from the index, not the working tree?
A:   $ git reset <file> removes just from the index, not the working tree. It is an opposite of git add.

Q: How can I reset local changes? Revert a file in the working copy to the HEAD/revision?
A:    $ git checkout <file> - checking out the version from the HEAD will overwrite local changes. Or $ git reset --hard <file>
Q: How to revert a commit? How to revert several consequent commits.
A:     $ git reset --hard HEAD~1 This reverts the last commit (the HEAD one). HEAD~2 - reverts 2 last commits, etc.
If you want to revert the commits in the "middle" e.g

Q: How to remove a file from the repository, but keep it in the working tree?
A:   $ git rm --cached <file>

ubuntu 11.10: java installation

2011-11-12T17:45:00.001+02:00

In ubuntu 11.10 sun-java6 is no longer in the repositories. It is *suggested* to install openjdk. I decided to give it a try.
Earlier I was kinda cautious regarding it, but now, since sun's (oracle's) jdk is not in favor, lets follow the trend. So choose what you need installed:

jdk -> $ sudo apt-get install openjdk-6-jdk

jre -> $ sudo apt-get install openjdk-6-jre

browser plugin -> $ sudo apt-get install icedtea6-plugin

Well, I have issues with icedtea plugin-my ibank2 applet (internet banking) is not working properly, so I had to get back sun's plugin.
I've downloaded the jre, installed it (it basically just unpacks itself). The you need to symlink the plugin. (2 options, root and non root). Assuming you've installed jre into /mnt/wind/bin/java/sun-java/

#install for all. Root version
$ sudo ln -s /mnt/wind/bin/java/sun-java/jre1.6.0_29/lib/amd64/libnpjp2.so /usr/lib/mozilla/plugins/

#if you want a non root install. Just for one user:
$ mkdir -p ~/.mozilla/plugins
$ ln -s /mnt/wind/bin/java/sun-java/jre1.6.0_29/lib/amd64/libnpjp2.so ~/.mozilla/plugins/

Now you should have sun's browser plugin in firefox and chrome!
If you want sun jre to be the default one, you need to manually update the system to let it know that a new java is present via update-alternatives. See man page, it's good.

P.S. If you find it helpful - feel free to click on some ads :)

zsh tips: path and full history

2011-11-12T17:35:00.001+02:00

I've switched from bash to zsh, and have some tips coming.

Q: history command on zsh doesn't return full history.
On bash when you run $ history you get the full history starting from the 1st command it has remembered. zsh returns just a small subset of history.

A: run $ history 1 i.e. say explicitly that you want history from the 1st line

Q: reread the PATH to update the list of available executables. When installing an app in bash it is available right away. After the installation in zsh you cannot tab-complete the newly installed app. You can still run it if you know the name though.

A: need to rehash. run $ hash -r

Bluetooth on ubuntu 11.10

2011-11-05T13:07:00.001+02:00

Updated 01.12.2011
Bluetooth is something that's supposed to be simple and work out of the box but frequently is not working at all.
That's why every time I install a new OS I test if bluetooth is working.

So, fresh ubuntu 11.10, client is Samsung Galaxy phone, let's see what works in ubuntu.
Receiving files works fine.Update: receiving fails if you're sending to Windows Mobile phone!
Pairing initiated from the computer works fine.
Sending files - failed with the a 'permission denied error'. After searching/asking I've come across a bug report.Update: sending works if you send to a Windows Mobile device.
So on ubuntu 11.10 this is the summary picture for send/receive:

Since I still need to send files I have to mount my phone with obexfs. In short:

install obexfs
pair the phone with the PC (works from the gui)
Get the device MAC and mount it with obexfs:

$ sudo apt-get install obexfs

$ hcitool scan

Scanning ...
8F:77:17:77:44:16 My Android Phone

<your device is found and mac listed>
$ obexfs -b 8F:77:17:77:44:16 /mountpoint

To unmount the device:
$ fusermount -u /mountpoint

Source: great wiki.

Pairing from the phone: No longer fails after I've updated blueman to the latest 1.23 version. If it's not in your repo run

$ sudo add-apt-repository ppa:blueman/ppa

$ sudo apt-get update

$ sudo apt-get upgrade

build plasmoid in kubuntu

2011-10-29T17:41:00.001+03:00

http://kde-look.org/ is a great source of KDE customization.
Being a new to KDE I had to have some pain building a plasmoid - plasma desktop widget.
I wanted this
First, always trying to find the package in the repos. Then - binary download. Here, the download is the source code, so it has to be built. The page itself doesn't have any instructions. Sounds familiar... :)
The package contains readme with build instructions.

Installation
============

To build and install:

1. mkdir build
2. cd build
3. cmake .. -DCMAKE_INSTALL_PREFIX=`kde4-config --prefix`
4. make
5. sudo make install

Looks ... different, but simple.
On a fresh install we need the following packages:
build-essential, cmake. Get them with

$ sudo apt-get install build-essential cmake

Running the cmake shows some not found errors. So I had to install apt-file to find what I miss.
$ sudo apt-get install kdelibs5-dev kdebase-workspace-dev libdbusmenu-qt-dev

The last one - dbus library - was tricky to find since even that I knew it should be dbus-menu-dev package, it wasn't in the repo. The exact name was a lucky find...

Finally, install. Unfortunately, installing with checkinstall failed. I'm getting frustrated with it, since it is not the first time it fails..

copy directory structure, copy files with directories

2011-07-12T16:56:00.000+03:00

Q. How can I copy a directory tree without copying files?
A. Enter the root of the tree you want to copy. The tree will be recreated under /destination/

$ find -type d | xargs -i mkdir -p /destination/{}

Q. How can I copy the files and recreate the directory tree the file is in. I.E. copy the file along with the whole or part of the directory tree.
A. Enter the folder you want to be the root of the copied tree. Suppose I have /home/me/work/urgent/files/x.htm copied to /destination/ starting from me/ folder. Enter /home/ and type:

$ echo me/work/urgent/files/x.htm | cpio -pdvm /destination/

#search for files and copy all found with their dir trees

$ find . -name '*.htm' |cpio -pdvm /destination/

Mount a virtualbox VDI hard disk on ubuntu linux

2011-07-10T10:18:00.000+03:00

Shut down the VBox VM you want to mount.

#install tools

$ sudo apt-get install qemu-kvm

#load module

$ sudo modprobe nbd

#create loopback dev for the image

$ sudo qemu-nbd -c /dev/nbd0 <image>.vdi

#mount the partitions, that are exposed as /dev/nbd0pXXX

$ sudo mount -o noatime,noexec /dev/nbd0p1 /tmp/vdi/

#in the end unmount && shutdown the ndb

$ sudo umount /tmp/vdi/

$ sudo qemu-nbd -d /dev/nbd0

Another way (longer but without nbd)
resources:
forum
blog

If you find the tip helpful - feel free to click the ads :)

Backup and restore all installed packages

2011-07-07T16:00:00.000+03:00

Before, make sure you backup your apt sources
For backup, list all installed packages:

$ sudo dpkg --get-selections > packages.txt

To restore the list do:

$ sudo dpkg --clear-selections
$ sudo dpkg --set-selections < packages.txt
$ sudo apt-get dselect-upgrade

backup list of ppa sources

2011-06-28T13:24:00.000+03:00

The list of sources is in /etc/apt/sources.list and /etc/apt/sources.list.d/
Backup that file and that folder.
Additionally, backup the repository keys:

$ sudo apt-key exportall > ~/repositories.key

And restore
$ sudo apt-key add /path/to/repositories.key

Sluggish flash player in fullscreen mode on ubuntu

2011-04-30T10:40:00.001+03:00

Symptoms: flash player videos are slow in full screen mode, fps drops to 1-2, although th video is playing just fine in normal mode.

Solution:
Create a file /etc/adobe/mms.cfg with content "OverrideGPUValidation = 1"
(including " ")
Or use the commands:
$ sudo mkdir /etc/adobe
$ sudo echo "OverrideGPUValidation = 1" >> /etc/adobe/mms.cfg

Creating a folder with limited size

2011-02-12T15:02:00.000+02:00

To create a folder with fixed size, one of the solutions is to create a limited size filesystem and mount it.

Create a file that will be a container of the filesystem. Just take ANY file on your system that has a suitable size, or create one by

$ dd if=/dev/null of=~/myfs bs=SIZE_OF_BLOCK_IN_BYTES count=SIZE

Format the file with the FS you want

$ mkfs.ext4 ~/myfs

It will say that it creates an FS on a non-block device.

Mount the FS

mount -o loop,rw,usrquota,grpquota ~/myfs /path/of/mount/point