set -u for undefined variable errors in Bash Scripting - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to enable error on undefined variables.

Bash Scripting

set [1]

Drag options to blanks, or click blank then click option'

A-e

B-x

C-u

D-v

Attempts:

3 left

💡 Hint

Common Mistakes

Using -e instead of -u disables exit on error, not undefined variables.

Using -x enables debugging output, not error on undefined variables.

The set -u option makes the shell treat unset variables as an error when substituting.

2fill in blank

medium

Complete the script to exit on undefined variable usage.

Bash Scripting

#!/bin/bash
set [1]
echo "$MY_VAR"

Drag options to blanks, or click blank then click option'

A-e

B-u

C-x

D-v

Attempts:

3 left

💡 Hint

Common Mistakes

Using -e only exits on command errors, not unset variables.

Forgetting to use set -u leads to silent empty variable expansion.

Using set -u causes the script to exit if MY_VAR is not set.

3fill in blank

hard

Fix the error by completing the code to enable undefined variable errors.

Bash Scripting

set [1]
if [ -z "$UNDEF_VAR" ]; then
  echo "Variable is empty"
fi

Drag options to blanks, or click blank then click option'

A-e

B-v

C-x

D-u

Attempts:

3 left

💡 Hint

Common Mistakes

Using -e does not catch unset variables.

Not using set -u allows silent empty variable usage.

Using set -u causes the script to error if UNDEF_VAR is not set, preventing silent empty checks.

4fill in blank

hard

Fill both blanks to enable error on undefined variables and print a message.

Bash Scripting

set [1]
echo "Value: $[2]"

Drag options to blanks, or click blank then click option'

A-u

BMY_VAR

CUNSET_VAR

D-e

Attempts:

3 left

💡 Hint

Common Mistakes

Using -e instead of -u for the option.

Using an undefined variable name causes script to exit.

set -u enables error on undefined variables. Using MY_VAR prints the variable value.

5fill in blank

hard

Fill all three blanks to enable error on undefined variables, assign a value, and print it.

Bash Scripting

set [1]
[2]="Hello"
echo "Message: $[3]"

Drag options to blanks, or click blank then click option'

A-u

Bgreeting

D-e

Attempts:

3 left

💡 Hint

Common Mistakes

Using -e instead of -u for the option.

Using different variable names for assignment and print.

set -u enables error on undefined variables. We assign greeting and print it.