Tilde expansion (~) in Bash Scripting - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of this command?

Consider the following bash command run by user 'alice' whose home directory is '/home/alice':

echo ~

What will be printed?

Bash Scripting

echo ~

A /root

B ~

C /home

D /home/alice

💡 Hint

The tilde (~) expands to the current user's home directory in bash.

In bash, the tilde (~) alone expands to the home directory of the current user. Since the user is 'alice', it expands to '/home/alice'.

💻 Command Output

intermediate

What does this command output?

Given that user 'bob' exists with home directory '/home/bob', what is the output of:

echo ~bob

when run by user 'alice'?

Bash Scripting

echo ~bob

A /home/bob

B ~bob

C /home/alice

D Error: user not found

💡 Hint

Tilde followed by a username expands to that user's home directory.

In bash, ~username expands to the home directory of that user. Since 'bob' exists with home '/home/bob', it expands accordingly.

📝 Syntax

advanced

Which command correctly uses tilde expansion to list files in the home directory?

You want to list all files in your home directory using tilde expansion. Which of the following commands will work correctly?

A ls '~/'

B ls "~/"

C ls ~/

D ls ~

💡 Hint

Tilde expansion does not occur inside quotes.

Tilde expansion happens only when the tilde is unquoted. Option C uses unquoted ~/, so it expands correctly. Options B and C quote the tilde, so no expansion occurs. Option C works but lists the home directory without trailing slash, which is valid but less explicit.

💻 Command Output

advanced

What is the output of this command?

Assuming user 'carol' has home directory '/home/carol', what is the output of:

echo ~carol/Documents

when run by user 'dave'?

Bash Scripting

echo ~carol/Documents

A /home/carol/Documents

B ~carol/Documents

C Error: user carol not found

D /home/dave/Documents

💡 Hint

Tilde expansion works with usernames followed by paths.

The tilde with username expands to that user's home directory, and the rest of the path is appended. So it becomes '/home/carol/Documents'.

💻 Command Output

expert

What is the output of this script snippet?

Consider this bash script snippet run by user 'eve' whose home directory is '/home/eve':

dir=~
echo "$dir"

What will be printed?

Bash Scripting

dir=~
echo "$dir"

A /home/eve

B ~

C Error: invalid assignment

D $HOME

💡 Hint

Tilde expansion does not happen during variable assignment without evaluation.

When assigning dir=~, the tilde is not expanded because tilde expansion happens only in unquoted command arguments, not in variable assignments. So dir contains the literal '~'.