Function libraries (sourcing scripts) in Bash Scripting - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does it mean to 'source' a script in Bash?

Sourcing a script means running it in the current shell session so that functions and variables defined in it become available immediately without starting a new shell.

beginner

How do you source a script named library.sh in Bash?

Use the command source library.sh or the shorthand . library.sh to include the script in the current shell session.

beginner

Why use function libraries in Bash scripting?

Function libraries let you reuse code easily by keeping common functions in one file. You can source this file in many scripts to avoid rewriting the same code.

intermediate

What happens if you run a script normally instead of sourcing it when you want to use its functions?

Running a script normally starts a new shell, so functions and variables defined inside it won't be available in your current shell session.

intermediate

How can you check if a function library script was sourced successfully?

After sourcing, try calling a function from the library. If it runs without error, the sourcing worked. You can also check if the function is defined using type function_name.

Which command correctly sources a script named utils.sh?

A bash utils.sh

B ./utils.sh

C run utils.sh

D source utils.sh

The source command runs the script in the current shell, making its functions and variables available.

What is the main benefit of sourcing a function library script?

A It deletes the script after running.

B It runs the script in a new shell.

C It makes functions available in the current shell.

D It compiles the script.

Sourcing runs the script in the current shell, so functions and variables become accessible immediately.

If you run ./library.sh instead of sourcing it, what happens to the functions defined inside?

A They become available in the current shell.

B They are only available in the new shell started by the script.

C They are deleted.

D They run automatically in the current shell.

Running the script starts a new shell, so functions stay local to that shell and do not affect the current one.

Which symbol is a shorthand for the source command in Bash?

A .

B &

C #

D $

The dot . is a shorthand for source in Bash.

How can you verify if a function named greet is defined after sourcing a script?

A type greet

B run greet

C check greet

D find greet

The type command shows if a function or command is defined in the current shell.

Explain what sourcing a script means and why it is useful in Bash scripting.

Think about how sourcing affects your current shell session.

Describe the difference between running a script normally and sourcing it, especially regarding function availability.

Consider where the functions live after each method.