Tuxfreaks

Ahem!!An Update from Tuxfreaks.There will be  2 Posts a month exclusively for the linux beginners .I need to drive some traffic[:P].As the title says, it is just not for the beginners but also comes handy to the evry Linux user.So here we Go

How to find out which application or process is using your port

The simplest way to find is to use lsof command
Example :If i need to find which application is using the port  61136,i need to

lsof -i tcp:61136

which gives me the output:
COMMAND    PID   USER   FD   TYPE DEVICE SIZE NODE NAME
uTorrent. 3364 kranny   19u  IPv4  10656       TCP *:61136 (LISTEN)

Covert Ext2 to Ext3 Filesystem

Ext3  is a journal extended file system and journalized file system are always advantageous than non-journalized ones(Ext2).so i adivise using ext3 and plan ahead for ext4 with -I 256 byte i nodes.Don’t confuse with the word journaling,for the time being just understand that  you don’t have to fsck after a crash.

To convert partition to the ext3 filesystem,cleanly unmount them and,on a console,

tune2fs -j /dev/hdaX

Modify the lines in your /etc/fstab to reflect that the partitions in question are to be mounted as ext3.you are just a reboot faraway from making  your partitions as ext3.

Default behavior of Ctrl+Alt+Delete

Many of the windows users out there might have the habit of pressing the Ctrl+Alt+Del keys whenever any process hangs.It opens up the task manager and you can proceed form there.But the Default behavior in Linux is to reboot the system.Imagine u have not saved any of your work and used the combination of those keys.Before you curse yourself for doing so,Why dont you change the behaviuor of it.

Modify Ctrl-Alt-Del Behavior in Linux

I hate the Ctrl-Alt-Del combination, maybe because it reminds me of the unpleasant days when I used other operating systems. If you want to modify it, then here is how to do this:

In Ubuntu

Open the file /etc/event.d/control-alt-delete  (You need super user privileges)

You should see a line similar to this:

exec /sbin/shutdown -r now “Control-Alt-Delete pressed”

Which binds ctrl-alt-del to rebooting your computer. Change it to execute any other program you want. Of course you can disable it completely by commenting the whole file.Open /etc/inittab file and you should see something like this:

ca:12345:ctrlaltdel:/sbin/shutdown -t1 -a -r now

To disable ctrl-alt-del, just comment this line. To bind it with other program, just replace “/sbin/shutdown -t1 -a -r now” with the program you want to execute.

In Ubuntu you dont have the inittab file.Instead modify /etc/event.d/control-alt-del file

exec /sbin/shutdown -r now “Control-Alt-Delete pressed”

change it to

exec /usr/bin/gnome-system-monitor

or anyother program you wish to invoke.

Save Your Command History Of a Session

Did you ever think how handy it is to save the command history to a file and use it for future reference.Its just a matter of two commands and there you go.

root@kranny-desktop$ script filename

and there starts your logging until you type exit

root@kranny-desktop$exit

You can view the history in the file “filename”

To kill a process/hung up GUI Application

It is indeed easy to kill a process issuing the kill command with the respective process PID as an argument.Well its a long process to find out the PID of the process you are going to terminate.how about this?If you want to kill firefox

pgrep firefox | xargs kill

And if you want to kill a GUI application,open up your terminal and type

xkill

This would change your cursor to a ‘X’ and just click on the window you would like to terminate