Master the Linux tee Command: Real‑World Examples and Tips

When working in a Linux terminal you may need to write data to a file while still processing its output; the tee utility makes this possible.

What is the tee command?

The tee command reads from standard input and writes to both standard output (your screen) and one or more files, similar to a T‑shaped pipe used by plumbers.

Installation

tee

is included in GNU Coreutils, so it is pre‑installed on most Linux distributions. Verify its presence with: which tee Check the version with:

tee --version

Basic syntax

The general form is: tee [options]... [file]... Common options: -a: Append to the file instead of overwriting. --version: Show the installed version. --help: List all available options.

Practical examples

1. Write ping output to a file while displaying it

ping yahoo.com | tee pingLinuxMi.txt

This captures the ping results in pingLinuxMi.txt while still showing them on the terminal.

2. Append data to a file

ping 192.168.174.170 | tee -a pingLinuxMi.txt

3. Write to multiple files simultaneously

[your command] | tee file1 file2 file3

4. Pipe tee output to another command

ls ~ | tee linuxmi.txt | wc -l

This lists files in the home directory, saves the list to linuxmi.txt, and counts the number of entries.

5. Ignore interrupt signals

[command] | tee -i output_file

The -i option prevents Ctrl+C (SIGINT) from terminating the pipeline.

6. Hide tee output

[command] | tee output_file > /dev/null

This writes the output to output_file while discarding it from the screen.

7. Use tee with sudo for privileged files

echo "300" | sudo tee /etc/linuxmi.conf

Redirects data to a file owned by the root user without permission errors.

Conclusion

With these examples you should now understand how to use tee for everyday tasks, from simple logging to complex pipelines.