Question

This assignment will assess your ability to write bash scripts.

• Drop​ ​down​ ​to​ ​the​ ​root​ ​user​ ​using​ ​the​ ​command​ ​sudo su -.​
• Write a bash script named /root/exam02.sh that does the following:
  • Takes exactly 1 argument.
  • If the number of arguments is not 1:
    • Print "Exiting!" and exit with return code 40.
  • If the number of arguments is exactly 1:
    • Print the first argument as per the example below.

Example output for your reference:

The script should have the following output when run with 0 or 2+ arguments:

# /root/exam02.sh
Exiting!
# echo ${?}
40

# /root/exam02.sh testarg1 testarg2
Exiting!
# echo ${?}
40

The script should have the following output when run with exactly 1 argument:

# /root/exam02.sh testarg1
Arg1: testarg1

Answer 1

1. Go to the root directory

HomeworkLib@Chegg-PC:~$ sudo su
[sudo] password for HomeworkLib:

root@Chegg-PC:/home/HomeworkLib# cd

root@Chegg-PC:~# pwd
/root

2. Write script using vi editor

root@Chegg-PC:~# vi /root/exam01.sh

~

~

"~/exam02.sh" 1 line, 1 character

3. Script:

#!/bin/bash

if [ $# -ne 1 ]
then
   echo "Exiting!"
   exit 40
elif [ $# -eq 1 ]
then
   echo "Arg1:" $1
fi

4. Run and Output:

root@Chegg-PC:~# sh /root/exam02.sh
Exiting!
root@Chegg-PC:~# echo $?
40
root@Chegg-PC:~# sh /root/exam02.sh testarg1 testarg2
Exiting!
root@Chegg-PC:~# echo $?
40
root@Chegg-PC:~# sh /root/exam02.sh testarg1
Arg1: testarg1