touch (create empty files) in Linux CLI - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of this command sequence?

You run these commands in a Linux terminal:

touch file1.txt
ls -l file1.txt

What will the ls -l file1.txt command show about file1.txt?

Linux CLI

touch file1.txt
ls -l file1.txt

A Shows an error: file1.txt does not exist

B Shows file1.txt with size 100 bytes and current timestamp

C Shows file1.txt with size 0 bytes and current timestamp

D Shows file1.txt with size 0 bytes but timestamp from yesterday

💡 Hint

The touch command creates an empty file or updates the timestamp if it exists.

The touch command creates an empty file if it doesn't exist, so the file size is 0 bytes. The timestamp is set to the current time.

💻 Command Output

intermediate

What happens when you run touch on an existing file?

Suppose example.txt already exists with some content.

You run:

touch example.txt

What changes after this command?

Linux CLI

touch example.txt

A Nothing happens; file remains unchanged

B The file content is erased and size becomes 0 bytes

C The file is deleted

D The file content stays the same but the modification timestamp updates to current time

💡 Hint

Touch updates timestamps without changing file content.

Touch updates the modification and access timestamps to current time without changing the file content or size.

📝 Syntax

advanced

Which touch command creates multiple empty files at once?

You want to create three empty files named a.txt, b.txt, and c.txt in one command.

Which command does this correctly?

A touch a.txt b.txt c.txt

B touch a.txt; b.txt; c.txt

C touch a.txt && touch b.txt && touch c.txt

D touch a.txt,b.txt,c.txt

💡 Hint

Touch accepts multiple filenames separated by spaces.

The touch command can take multiple filenames separated by spaces to create multiple files at once.

💻 Command Output

advanced

What error occurs when using touch on a directory without permissions?

You try to run:

touch /root/secret.txt

But you are a normal user without root permissions.

What is the expected output?

Linux CLI

touch /root/secret.txt

A touch: command not found

B touch: cannot touch '/root/secret.txt': Permission denied

C File /root/secret.txt created successfully

D No output, command runs silently

💡 Hint

Normal users cannot write files in root-owned directories.

Without permission, touch cannot create or update files in /root and shows a permission denied error.

🚀 Application

expert

How to create an empty file only if it does not exist using touch?

You want to create an empty file named log.txt only if it does not already exist.

Which command achieves this without changing the timestamp if the file exists?

A touch -c log.txt

B touch -a log.txt

C touch -t log.txt

D touch -n log.txt

💡 Hint

The -c option prevents creating a new file if it doesn't exist.

The touch -c option updates timestamps only if the file exists; it does not create a new file.