Tracing and debugging
 

If I want to trace my C program line by line while execution and identify the errors if any, how can I do? Any command lione utility or X-server utility that is available that I can make use of?

use gdb

When you compile your code:

cc -g myfile.c -o myfile

gdb myfile
>br main
>run
>step for each line of code

> help gives you help inside gdb

Thank you. So, I will start learning the gdb utility.

There are also e few GUI interfaces to gdb: ddd, xgdb.
They're probably included in you distro.
I prefer running gdb in emacs. It has the normal command interface of gdb, but at least you see the sources in an editor as you step through it.