Posts Tagged ‘tiny article’

Remove password prompt on GNOME Shutdown / Restart on Debian and Ubuntu Linux

Saturday, June 1st, 2013

It is ultra annoying, that in newest Debian and Ubuntu releases with GNOME 3 Desktop environment on every shutdown or restart you need to type in Super User (root) password, to authorize shutdown / restart.

Generally prompting for root password on GNOME restart is obviously a good think from security point of view, but from usability one – especially on notebooks it is useless annoyance…

So after changing this behavior I came up with this tiny article on how to get rid of GNOME Shutdown / Restart password prompt.

There is a click button (on left of Auth prompt on Shutdown showing URL to XML policy rule from where this behavior is controlled. A really good hint to where to look for to change those annoying behavior…

 Here is how to change this new annoying behavior to old GNOME 2 default restart with no root password prompt .
linux:~# gedit /usr/share/polkit-1/actions/org.freedesktop.consolekit.policy

Find in XML source sections:

Restart the system when multiple users are logged in System policy prevents restarting the system when other users are logged in no auth_admin_keep
Stop the system when multiple users are logged in System policy prevents stopping the system when other users are logged in no auth_admin_keep

To change Restart and Shutdown GUI behavior to not prompt for password, you need to modify in above code:



After changes both sections should look like so:

<action id="org.freedesktop.consolekit.system.restart">
<description>Restart the system</description>
<message>System policy prevents restarting the system</message>

<action id="org.freedesktop.consolekit.system.restart-multiple-users">
<description>Restart the system when multiple users are logged in</description>
<message>System policy prevents restarting the system when other users are logged in</message>

That's all you finally get rid of the annoying prompt for root password. Enjoy 🙂

Add line numbering to text file with prefix text on Linux with awk

Monday, March 25th, 2013


Recently I blogged a tiny article on how to add line numbering to ASCII text files with nl cmd. Today I needed to do the same line numbering, except I wanted to add a prefix text "R0" to each line number to match requirements of program which will later take use of .txt database file. I looked through nl (number lines) command manual but didn't find option with which I can insert a prefix string to each numbered line. I'm not a regular expression GURU, thus I asked for some help in on how to do it. Thanks to the kind guys in #bash I got it.

Here is how to add line numbering starting from 01onwards by adding a text prefix "R0":

$ awk '{ printf "R0%02d %s\n", NR, $0 }' text_file_to_number.txt > numbered_text_file_with_prefix.txt

The file to number in my case included a huge text file containing verses from Holy Bible, here is few lines from it before and after parsing and numbering with string prefix:


In the beginning God created the heaven and the earth.
                — Genesis 1:1
And the earth was without form, and void; and darkness was upon
the face of the deep. And the Spirit of God moved upon the face of
the waters.
                — Genesis 1:2
And God said, Let there be light: and there was light.
                — Genesis 1:3


R001 In the beginning God created the heaven and the earth.
R002            — Genesis 1:1
R003 %
R004 And the earth was without form, and void; and darkness was upon
R005 the face of the deep. And the Spirit of God moved upon the face of
R006 the waters.
R007            — Genesis 1:2
R008 %
R009 And God said, Let there be light: and there was light.
R010            — Genesis 1:3



To add any other prefix except R0 for example SAMPLE_PREFIX_STRING, substitute in above awk expression R0 with whatever expression;


awk '{ printf "SAMPLE_PREFIX_STRING%02d %s\n", NR, $0 }' text_file_to_number.txt > numbered_text_file_with_prefix.txt

Linux: Convert recursively files content from WINDOWS-CP1251 to Unicode UTF-8 with recode and iconv

Wednesday, January 9th, 2013


Linux How to make mass file convert of charset windows CP1251 toutf8 and to other encodings

Some time ago I've written a tiny article, explaining how converting of HTML or TEXT file content inside file can be converted with iconv.

Just recently, I've made mirror of a whole website with its directory structure with wget cmd. The website to be mirrored was encoded with charset Windows-1251 (which is now a bit obsolete and not very recommended to use), where my Apache Webserver to which I mirrored is configured by default to deliver file content (.html, txt, js, css …) in newer and more standard (universal cyrillic) compliant UTF-8 encoding. Thus opening in browser from my website, the website was delivered in UTF-8, whether the file content itself was with encoding Windows CP-1251; Thus I ended up seeing a lot of monkey unreadable characters instead of Slavonic letters. To deal with the inconvenience, I've used one liner script that converts all Windows-1251 charset files to UTF-8. This triggered me writting this little post, hoping the info might be useful to others in a similar situation to mine:

1. Make Mass file charset / encoding convertion with recode

On most Linux hosts, recode is probably not installed. If you're on Debian / Ubuntu Linux install it with apt;

apt-get install --yes recode

It is also installable from default repositories on Fedora, RHEL, CentOS with:


yum -y install recode

Here is recode description taken from man page:

       recode – converts files between character sets

find . -name "*.html" -exec recode WINDOWS-1251..UTF-8 {} \;

If you have few file extensions whose chracter encoding needs to be converted lets say .html, .htm and .php use cmd:

find . -name "*.html" -o -name '*.htm' -o -name '*.php' -exec recode WINDOWS-1251..UTF-8 {} \;

Btw I just recently learned how one can look for few, file extensions with find under one liner the argument to pass is -o -name '*.file-extension', as you can see from  example, you can look for as  many different file extensions as you like with one find search command.

After completing the convertion, I've remembered that earlier I've also used iconv on a couple of occasions to convert from Cyrillic CP-1251 to Cyrillic UTF-8, thus for those who prefer to complete convertion with iconv here is an alternative a bit longer method using for cycle + mv and iconv.

2. Mass file convertion with iconv

for i in $(find . -name "*.html" -print); do
iconv -f WINDOWS-1251 -t UTF-8 $i > $i.utf-8;
mv $i $i.bak;
mv $i.utf-8 $i;

As you see in above line of code, there are two occurances of move command as one is backupping all .html files and second mv overwrites with files with converted encoding. For any other files different from .html, just change in cmd find . -iname '*.html' to whatever file extension.

How to delete MySQL user using mysql cli command

Monday, September 24th, 2012

I decided to clean up a bit my MySQL obsolete users. I use to test free software every now and then and often in the hurry I forgot to clean up the respective soft database and created user in database/table mysql.user.

This is how this tiny article get born. Deleting users in version MySQL 5.0 and higher use command:

mysql> DROP USER username@localhost;

On older MySQL versions; 3.x / 4.x the SQL query is a bit longer:

mysql> DELETE FROM user WHERE User= 'type_your_user_name_here' AND Host= 'localhost'; mysql> FLUSH PRIVILEGES;

Well that's all, now user is wiped out, Enjoy 🙂

Controlling fan with Thinkfan on Lenovo Thinkpad R61 on Debian GNU/Linux (adjusting proper fan cycling)

Saturday, August 7th, 2010

Some time ago before I have blogged about How to properly control your Lenovo Thinkpad R61 fan rotation cycles on Linux with ThinkFan
In this tiny article I have explained my previous obstacles of making my Notebook CPU cooling fan to properly rotate and cool up my Central Processing Unit.

However just recently I’ve upgraded my Debian Unstable – Squeeze/Sid through the apt-get manager to the newest possible package updates.
The upgraded bundle of packages also updated my sid thinkfan package to:

hipo@noah:~$ dpkg -l |grep -i thinkfan
ii thinkfan 0.7.1-1 simple and lightweight fan control program

I was unpleasently suprised when I tried to restart thinkfan using the thinkfan init.d script I have used until recently /etc/init.d/thinkfan , cause /etc/init.d/thinkfan was no longer be.

Furthermore I give a try to directly launch the thinkfan daemon from the terminal trying to backround the service, like so:

noah:~# thinkfan &
WARNING: Using default temperature inputs in /proc/acpi/ibm/thermal.
WARNING: You have not provided any correction values for any sensor, and your fan will only start at 55 °C. This can be dangerous for your hard drive.

Though this started up the thinkfan daemon as you can see the note in the message below it started up with a consistent cycling cooling to keep the CPU wamrth sticked to 55 ° degrees: