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-   -   Shell Tips & Tricks - Part 2 (http://www.go4expert.com/articles/shell-tips-tricks-part-2-t19106/)

pradeep 20Aug2009 16:51

Shell Tips & Tricks - Part 2
 
Part I - Shell Tips & Tricks

Clear and Disable Bash History



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

Ampersand (Background Jobs)



& 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

Search An Replace in vi



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.

asha 26Aug2009 10:48

Re: Shell Tips & Tricks - Part 2
 
Cool, the history one was really nice, it really helps me ;-)

shabbir 2Sep2009 18:56

Re: Shell Tips & Tricks - Part 2
 
Nomination for Article of the month - Aug 2009 Started.

shabbir 19Sep2009 11:41

Re: Shell Tips & Tricks - Part 2
 
Vote for this article for Article of the month - August 2009


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