1. How do you write a while loop in shell?

while {condition} do {statement} done

2. How does a case statement look in shell scripts?

case {variable} in {possible-value-1}) {statement};; {possible-value-2}) {statement};; esac

3. How do you read keyboard input in shell scripts?

read {variable-name}

4. How do you define a function in a shell script?

function-name() { #some code here return }

5. How do you stop all the processes, except the shell window?

kill 0

6. How do you find out about all running processes?

ps -ag

7. How do you stop a process?

kill pid

8. What's the command to find out today's date?

date

9. What's the command to find out users on the system?

who

10. How do you find out the current directory you're in?

pwd

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11. How do you write a for loop in shell?

for {variable name} in {list} do {statement} done

12. What's a way to do multilevel if-else's in shell scripting?

if {condition} then {statement} elif {condition} {statement} fi

13. How do you find out the number of arguments passed to the shell script?

$#

14. How do you do Boolean logic operators in shell scripting?

! tests for logical not, -a tests for logical and, and -o tests for logical or.

15. How do you test for file properties in shell scripts?

-s filename tells you if the file is not empty, -f filename tells you whether the argument is a file, and not a directory, -d filename tests if the argument is a directory, and not a file, -w filename tests for writeability, -r filename tests for readability, -x filename tests for executability

16. How do you do number comparison in shell scripts?

-eq, -ne, -lt, -le, -gt, -ge

17. What's the conditional statement in shell scripting?

if {condition} then … fi

18. How do you refer to the arguments passed to a shell script?

, and so on. {xtypo_info}$1, $2 and so on. $0 is your script name.{/xtypo_info} is your script name.

19. How do you fire a process in the background?

./process-name &

20. How do you find out what's your shell?

echo $SHELL

21. How do you list currently running process?

ps

22. How do you search for a string in a directory with the subdirectories recursed?

grep -r string *

23. How do you search for a string inside a directory?

grep string *

24. How do you search for a string inside a given file?

grep string filename

25. How do you count words, lines and characters in a file?

wc

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26. How do you find out your own username?

whoami

27. How do you remove recursively?

rm -rf

28. How do you remove a file?

rm

29. How do you send a mail message to somebody?

mail somebody@globalguideline.com -s ‘Your subject' -c ‘ cc@globalguideline.com‘

30. What are PIDs?

They are process IDs given to processes. A PID can vary from 0 to 65535.