Debugging Under Linux

in these hard days in Iran college term finished, being stuck at home, nothing better to do than working programming projects .
last night I didn't sleep because the program that I wrote was giving me strange crushes and I was pulling out my hairs .

I found this great great tool to debugg programs in linux called gdb .


let me show you few examples of how it works .
after installing it .
- go to your program's source code directory .
- type this in terminal

gdb

- now run your binary file to debugg

run name_of_your_binaryfile

it will give detailed errors of what happend

- there is another thing called Backtrace (a report of the active stack frames instantiated by the execution of a program )
after "run" you can type :

backtrace

-you can also do : breakpoint , which makes your program stop at certain points
for example you want a report to be given to you in the function1. you type :

b function1

-the last thing I teach you is, file
you can import another binary file to examine using :

file NAMEOFFILE

have fun with GDB .

[kubuntu] How to restore KDE panel, widgets just like fresh install

if you messed up the panels and widgets on your Kubuntu , and you wish you could have just like a fresh install panel and widgets here is what to do :
open a konsole :

kquitapp plasma

rm ~/.kde4/share/config/plasma-appletsr

and in the end :

plasma &

Enjoy !

the truth about 64bit ubuntu !

Being a loyal linux user since 2005 , I have tried everything , and I have been using 64bit Hardy Heron since its release but I couldn't get a Free 64bit CD of the Ubuntu 8.10 .
Canonical Company (the sponsor of ubuntu) doesnt' ship Free 64bit Ubuntu CDs anymore , in the past you could choose which architecture you want (32bit or 64-AMD) .
and nobody talked about it , neither Canonical nor ubuntu guys in the forums noticed that .

so I did a little research about it.

in university our professors tell us that a 64bit CPU is twice faster than a 32bit CPU just when you run a 64bit operation system on it.

but is 64bit ubuntu faster than 32 bit ubuntu ?

the 64bit Ubuntu is a simple re-compile of the 32bit source code and there is no optimization to take advantages of the 64bit circuits in your CPU , and I found out not only it is not faster but it is slightly "slower" than 32bit ubuntu . (Source)

64bit Ubuntu also has problems with Nvidia/ATI driver ,it used to have problem with Flash (not anymore) and compiz is buggy in 64bit ubuntu .

the only advantage of a 64bit ubuntu is for those who have more than 4GB RAM . (a 32bit CPU can not address more than 2^32= 4GB of a RAM) and those who need to work with files bigger than 3.2 GB (thats the biggest file size you can have in 32 bit environment)

therefore I am gonna install a fresh 32bit Kubuntu and forget about the 64bit until Ubuntu developers make a real-64 bit version (with optimized compile codes) .

by the way it would be better if Canonical was honest and would make an announcement about their not shipping 64bit version anymore instead of being quite and hoping nobody would notice it.

P.S : I made a topic in ubuntu forums, you can follow it .