Special variables ($0, $1, $#, $@, $?, $) in Bash Scripting - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print the name of the script being run.

Bash Scripting

echo "Script name is: [1]"

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

A$0

B$1

C$$

D$#

Attempts:

3 left

💡 Hint

Common Mistakes

Using $1 which is the first argument, not the script name.

Using $$ which is the process ID, not the script name.

The special variable $0 holds the name of the script being executed.

2fill in blank

medium

Complete the code to print the number of arguments passed to the script.

Bash Scripting

echo "Number of arguments: [1]"

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

A$0

B$@

C$#

D$?

Attempts:

3 left

💡 Hint

Common Mistakes

Using $@ which lists all arguments, not the count.

Using $? which shows the last command's exit status.

The special variable $# holds the count of arguments passed to the script.

3fill in blank

hard

Fix the error in the code to print all arguments as separate words.

Bash Scripting

echo [1]

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

A$#

B$0

C$?

D$@

Attempts:

3 left

💡 Hint

Common Mistakes

Using $# which gives only the number of arguments.

Using $0 which is the script name.

The special variable $@ expands to all arguments as separate words.

4fill in blank

hard

Fill both blanks to check if the last command succeeded and print its exit code.

Bash Scripting

if [ [1] -eq 0 ]; then
  echo "Success with exit code [2]"
fi

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

A$?

B$#

C$0

D$$

Attempts:

3 left

💡 Hint

Common Mistakes

Using $$ which is the process ID, not exit status.

Using $# which counts arguments, not exit status.

The special variable $? holds the exit status of the last command.

5fill in blank

hard

Fill all three blanks to print the script name, process ID, and all arguments.

Bash Scripting

echo "Script: [1]"
echo "PID: [2]"
echo "Args: [3]"

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

A$0

B$$

C$@

D$#

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up $@ and $# for arguments.

Using $? instead of $$ for process ID.

Use $0 for script name, $$ for process ID, and $@ for all arguments.