How to solve these challenges:

• To be consistent with the filenames and paths run the commands on Ubuntu. Install it locally in a VM or at a cloud provider. Use my referral link below to create your account on DigitalOcean and youll get $100 in credit over 60 days: https://m.do.co/c/f1d4debf213f

• Write your solution in a terminal and test it.

• If your solution is not correct, then try to understand the error messages, watch the video again, rewrite the solution and test it again. Repeat this step until you get the correct solution.

• Save the solution in a file for future reference or recap.

Challenge #1

• Create a script that takes an argument and tests if it's a file or not.

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Challenge #2

• Consider the solution from the previous challenge. Change it so that it tests if the script is run with exactly one argument.

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Challenge #3

• Create a script that clears the contents of a text file which is the scripts argument.

• Test that the argument is a file.

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Challenge #4

• Create a script that drops the packets from an IP address given by the user.

• Example: The command to drop the packets from 100.0.0.1 is: iptables -I INPUT -s 100.0.0.1 -j DROP

• Run the script as root and test the connection to different IP addresses.

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Challenge #5

• Change the solution from the previous challenge so that the IP address is given as the first argument of the script.

• Test that the script is run with exactly one argument.

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Challenge #6

• Develop a script that appends to a file the currently logged in users and the current date and time.

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Challenge #7

• Create a script that prompts the user for a character.

• If the character is Y, display "YES". If the character is N, display "NO". Use double quotes when displaying YES and NO. If the user enters any other character exit the script.

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Challenge #8

• Change the previous script this way: If the character is Y or y display "YES". If the character is N or n display "NO". If the user enters any other character exit the script. Use the OR operator (||) for testing the lowercase y and n.

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Challenge #9

• Create a script that takes exactly two arguments. The first argument is a shell command and the second argument is a string. The script will check if the string belongs to the output of the command.

Example: ./search_in_output.sh "ifconfig -a" "flags" will say if the string flags belongs to the output of ifconfig -a

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