How to access a directory as root/Super user in Linux?

In debian Linux if you are logged in as a ordinary(lower previleged user), then you cant access all the directories in the filesystem. Becayse if tge security restrictions. So, if you want to access a particular directory which needs the higher privelege(say /root) you have 2 choices.

1. By Terminal
Just open the terminal by
1) Applications -> Accessories -> Terminal
or
2) alt + f2 -> type "gnome-terminal"(witout quotes) & hit enter key

Now change yourself as root by issuing the command $su root & corresponding Password and access the directory what you want.

2. By GUI(using Nautilus)
Right click the directory which you want to access as super/root user. Then select the option "open as administrator".

Now it prompts you for the Admin(Root) password then it open that directory as a root user. so, now you can access all the files with read,write, execute permission.

Note: For getting the option "open as administrator" your system must installed the package "nautilus-gksu". If not install it first with the following command '$sudo apt-get install nautilus-gksu'(use without quotes,dollar symbol)

Note:(Am using BOSS Linux - a famous indian distro based on Debian developed by CDAC).

Want to see What happens during system bootup(Linux) & startup services/scripts

1. While booting the system boot it in single user mode.

i.e press ctrl+alt+f1 <- if you have any problem to see the terminal(No GUI splash image) with messages and informations do the following

Note:

In BOSS linux one can see the background startup services and their messages by pressing the F2 key

during startup of the system(i.e during the 'Splash image with boss logo' loaded)

2. While booting select the OS, in which you want to login using up/down arrow now press 'e'. It leads you to the grub menu and now you can edit the

booting options. So now we want to see the messages from the startup services for that just remove the phrase 'splash VGA=xyz quiet'. Then press "ctrl+x" to boot the system. By doing this we are just denying the splash image to load. So we can see the startup services and their messages.

Note: If the messages runs fast and moves in a flash, then just add 'sleep 50' in the startup script (those scripts in /etc/init.d/*) which you want to monitor.

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

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.

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)