Go4Expert - Shell Tips & Tricks

Use the Bash inbuilt history command:

Code:

history -c

To prevent writing of your Bash history to the history when you log out:

Code:

unset HISTFILE

& is a inbuild operator to fork processes.

"If a command is terminated by the control operator &, the shell executes the command in the background in a subshell"

Code:

[root@pradeep test]# sleep 60 &

[1] 32739

The process id is stored in a special variable $!

Code:

[root@pradeep test]# echo $!

32739

List all background jobs

Code:

[root@pradeep test]# jobs

[1]+  Running                 sleep 60 &

Killing any background job

Code:

[root@pradeep test]# kill %1

[1]+  Terminated              sleep 60

Open a text file in vi/vim and goto command mode by pressing ECS and then ':', the search and replace command will be like,

Code:

%s/oldString/NewString/g

You can also mention which lines should be affected by this, %s means all lines.

Code:

5,10 s/oldString/NewString/g

This will tell vi to make do replacing in lines 5 to 10. You may also use regex in your search expression.