Monday, March 28, 2011

Compiz 2 Desktop(instead of 4) problem... How to fix it?

Compiz is one of the superb package(window manager) that gives a nice 3d look and feel even apple's OS can't be compete with it.

Most of the new users who installed the Compiz got the problem of getting only 2 desktops instead of default 4. So, how could we fix it..

1. After installing the Compiz one got the menu entry in Systemtools.
so, Applications - > System tools - > Compiz fusion icon
If we click the that a new icon will be placed in the panel.

2. Now right click on that icon, we get a pop up options like.. compiz options, reload window manager, etc... find the settings manager and click on that.

3. Now we get compiz Configuration setting manager, in that select general tab. Then select General options.

4. In general Options select the Desktop size. In that there will be a slider with the name "Horizontal Virtual Size" with the value 2. Change it to the value (4) you wish(number of desktops). That's it.

The real thing you can create as much desktop as you wish..
Enjoy & experience the linux...

Note: Am using BOSS GNU/Linux.. (Debian derived) An Indian Linux Distro. for more info http://bosslinux.in/ http://wiki.bosslinux.in/
Want to read more about compiz. Refer wikipedia in this link http://en.wikipedia.org/wiki/Compiz

Friday, March 25, 2011

How to convert .ogv file into .mp4 file

1. Download the Handbrake-CLI software package from the following site. http://handbrake.fr/

2. Install the deb using the following command. $sudo dpkg -i

3. Now you got the command 'HandBrakeCLI'. now issued the command as follows
$HandBrakeCLI -i -o

thats all.

Wednesday, March 23, 2011

What is cron,crontab & how to use it?

Cron :
is a daemon process which checks the crontab every minute for checking is there any scheduled task to execute. After this checking it goes to sleep and waits for the next minute to wokeup and check the crontab. The cron daemon is one of the bootup process which starts running from the bootup of the system. If you want to check the cron daemon process, issue the following command in terminal

$ps -e | grep cron


Crontab(le) :
is a file which has the entries for scheduled tasks. The entries follows the following syntax.
M H DOM MOY DOW Task(command)
Where,
M -> Minute entry. Value range (0-59)
H -> Hour entry Value range (0-23)
DOM -> Day of Month Value range (1-31)
MOY -> Month of the Year Value range (1-12)
DOW -> Day of week Value range (0-6) where 0-Sunday, 1-Monday, ....

Example entry:1

Min Hour DOM MOY DOW Task

*   *    *   *   *   date  >> /tmp/every_minute.txt 


* <- means 'for all' The above entry will works on every minute and just appends the output of the command 'date' into the file '/tmp/every_minute.txt'. By opening the every_minute file in gedit you can see the output on every minute. If you want any other task to automate in the backend or chage the time when it needs to run configure the task entry as your need. Example entry:2
Min Hour DOM MOY DOW Task
30 22 * * * rm -r /tmp/*

The above entry will run everyday night 10.30(22.30) and removes everything from the /tmp/ Directory.

So how edit crontab:
In terminal type the following command
$crontab -e

Now the crontab file will opens in your default terminal editor(Mostly vi or vim). Now just add the Example 1 at the bottom of the file then save and exit.
Now open the /tmp/every_minute.txt file you can see it is updated each minute with the output of the date command.

For more information about cron, crontab
$man cron

$man 5 crontab


Location of files related to Cron :
Files in /var/spool/cron, /var/spool/anacron
Files in /etc/cron* ex. /etc/cront.d/, /etc/cront.weekly/
File /etc/crontab


Details Based on:
BOSS GNU/Linux (And most of the debian derived linux)

Tuesday, March 22, 2011

Want to see the Recently Installed/UnInstalled packages in your system?

We know that everything is loged in Linux. The installation, Uninstallation is not exception. The full details of latest installation, removal package is stored in the file

/var/log/apt/history.log

So if one accidently uninstalls a package and not know the name, he can easily find it in this log file. :)

Want to install "codec" for multimedia applications automatically?

In Linux some may face that some of their songs, videos(different formats) are not playing. So one need to install the corresponding plugins, codecs.
So what if when we try to play a song, video of new format the player itself findout the corresponding plugins and install by itself(Assumed you have internet conenction).

For this there is one package application called "gnome-codec-install" [Mostly it preinstalled in your Linux OS(Debian/Debian derived)]. If not installed prior. Just install it using

1. System -> Administration -> synaptic manager then serarch the package name and install.

2.In terminal $sudo apt-get install gnome-codec-install

So after successful installation when you try to play a song, video whose codec not installed yet will automaticall connect to the repository and installs then play.

Thursday, March 3, 2011

A simple way to setup a Centralised log Server in Linux

In Linux using UDP, or TCP we can send the logs of various machine into a single machine(Centralised log server).
We need to Configure the machines
1. Server machine - A centralised log server where all the logs are stored.
2. Client machine - which sends logs to the remote machine.

Server side configuration:
1. Open the /etc/rsyslog.conf and find the line "ModLoad" under the 'MODULES' part.

2. If you want to receive the logs by UDP then uncomment the following lines
$ModLoad imudp
$UDPServerRun 514

3. If you want to receive the logs by TCP then uncomment the following lines
#$ModLoad imtcp
#$InputTCPServerRun 514

Note: here 514 is port number

4. Edit the /etc/default/rsyslog file and change the RSYSLOGD_OPTIONS="-r -x -c1"

Note: -r <- Allow remotesystems to log their log entries into the server machine
-x <- Disables DNS lookups on messages received with -r
-c1 or -c2 <- Compatability mode (must not -c3 or -c4 because the compatability mode greater than 2 now allow remot log)

4.1 Restart the rsyslog by $sudo /etc/init.d/rsyslog restart
4.2 Now move to the Client side configuration. After the configuration finished restart the /etc/init.d/rsyslog there also
Now the remote logs are start logged in the log server machine you can veryfy them by $tail /var/log/auth.log. (change user in client machine and see that was logged in the auth.log)
If remote logs not works then do the following steps also in the log-server machine.

5. Open and edit the /etc/default/syslogd file and change the SYSLOGD as follows SYSLOGD="-r -m 0"
Now do the steps 4.1 & 4.2

6. Open and edit /etc/init.d/rsyslog file and change the RSYLOGD_OPTIONS into RSYLOGD_OPTIONS="-r" then do the steps 4.1 & 4.2




Client side configuration:
1. backup the /etc/rsyslog.conf file in anothername say $mv /etc/rsyslog.conf /etc/rsyslog.conf.bak

2. create a new /etc/rsyslog.conf file with the following content.
*.* @Logserver_ipaddress:portnumber


Thats it.. :)
Note: The linux distro am using is BOSS-4.0 (Debian based linux)