tee for splitting output in Linux CLI - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of tee command?

Consider the command:
echo "Hello World" | tee file.txt
What will be the output on the terminal?

Linux CLI

echo "Hello World" | tee file.txt

A file.txt

B Hello World

C No output

D Error: tee command not found

💡 Hint

tee prints the input to both the file and the terminal.

The tee command reads from standard input and writes to standard output and files. So the text is shown on the terminal and saved to file.txt.

💻 Command Output

intermediate

What happens when tee is used with -a option?

Given the command:
echo "New Line" | tee -a file.txt
What is the effect on file.txt?

Linux CLI

echo "New Line" | tee -a file.txt

A file.txt is overwritten with 'New Line'

B file.txt is deleted

C file.txt is appended with 'New Line'

D Error: invalid option -a

💡 Hint

The -a option means append.

The -a option tells tee to append the output to the file instead of overwriting it.

💻 Command Output

advanced

What is the output of tee with multiple files?

What will be the result of:
echo "Data" | tee file1.txt file2.txt
on the terminal and files?

Linux CLI

echo "Data" | tee file1.txt file2.txt

A Outputs 'Data' on terminal and writes to file1.txt and file2.txt

B Outputs 'Data' only on terminal, files remain empty

C Writes 'Data' only to file1.txt, no terminal output

D Error: tee accepts only one file

💡 Hint

tee can write to multiple files at once.

tee writes the input to standard output and all specified files.

💻 Command Output

advanced

What error occurs with invalid tee usage?

What error message appears when running:
echo "Test" | tee -z file.txt?

Linux CLI

echo "Test" | tee -z file.txt

A tee: invalid option -- 'z'

B Test

C No output, no error

D file.txt contains 'Test'

💡 Hint

Invalid options cause an error message.

The -z option is not valid for tee, so it prints an invalid option error.

🚀 Application

expert

How to save and display command output simultaneously?

You want to run ls -l and save its output to listing.txt while also seeing it on the terminal. Which command achieves this?

A ls -l >> listing.txt

B ls -l > listing.txt

C tee listing.txt < ls -l

D ls -l | tee listing.txt

💡 Hint

tee duplicates output to file and terminal.

Using tee after the pipe sends output to both the file and terminal.