Information
Room#
- Name: Bash Scripting
- Profile: tryhackme.com
- Difficulty: Easy
- Description: A Walkthrough room to teach you the basics of bash scripting
Write-up
Our first simple bash scripts#
What piece of code can we insert at the start of a line to comment out our code?
Answer: #
It's the same character as in most languages but if you don't know you can read the room material.
What will the following script output to the screen, echo "BishBashBosh"
Answer: BishBashBosh
echo just print the string passed as argument.
Variables#
What would this code return?
Answer: Jammy is 21 years old
You can write the script or evaluate the variables in your brain.
How would you print out the city to the screen?
Answer: echo $city
Simply echo the variable.
How would you print out the country to the screen?
Answer: echo $country
Simply echo the variable.
Parameters#
How can we get the number of arguments supplied to a script?
Answer: $#
Check the cheatsheet.
How can we get the filename of our current script(aka our first argument)?
Answer: $0
Check the cheatsheet.
How can we get the 4th argument supplied to the script?
Answer: $4
Check the course material.
If a script asks us for input how can we direct our input into a variable called 'test' using "read"
Answer: read test
The answer is in the question.
What will the output of "echo $1 $3" if the script was ran with "./script.sh hello hola aloha"
Answer: hello aloha
It will display 1st and 3rd args.
Arrays#
What would be the command to print audi to the screen using indexing.
Answer: echo ${cars[1]}
The second string is at index one.
If we wanted to remove tesla from the array how would we do so?
Answer: unset cars[3]
Use unset to remove an item.
How could we insert a new value called toyota to replace tesla?
Answer: cars[3]=toyota
Set a string at index 3.
Conditionals#
What is the flag to check if we have read access to a file?
Answer: -r
The first letter of read.
What is the flag to check to see if it's a directory?
Answer: -d
The first letter of directory.