Can you give me specific examples of
usage of awk utility.

This sounds like a homework question to me

So I will give a general answer in that awk is mainly used to search input, whether it be from a file or command run at the command line, for a specific pattern or patterns and then perform an action on that pattern.

For example, if you wanted to regularly kill a process in a script, but are not sure the PID of that process at any one moment in time, awk is good to search for that pattern and send the PID to the kill command thus:

kill -9 `ps -ef | grep $process | grep -v grep | awk '{print $1}'`

This is a very simply application of a relatively powerful and flexible language.

Search on the web for more on specific examples relating to awk.

Regards.

p.s you may need to modify the $ statement to print in the awk command to suit it to your system (most systems will list the username under the first column which is $1, and then the PID under second column which is $2 etc)