Combine `sudo` and `tee` for more tasks.

Using sudo and tee together is a "power move" in Linux. It's the standard way to write text to files that your normal user doesn't have permission to edit (like those in /etc).

Here are three practical tasks where this combination is extremely useful:

1. Appending to a System File

If you want to add a line to a protected file (like adding a new IP to /etc/hosts) without overwriting the whole file, use the -a (append) flag with tee.

echo "192.168.1.50 myserver.local" | sudo tee -a /etc/hosts

Why this is better than sudo echo ... >> /etc/hosts: Redirection (>>) is handled by the shell, not the command. Since your shell isn't running as root, >> would fail even if you used sudo echo. tee solves this because it runs as root.

2. Creating a Configuration File with Heredoc

You can use a Heredoc with sudo tee to create a multi-line configuration file in one go. This is very common when setting up web servers or repository lists.

sudo tee /etc/apt/sources.list.d/example.list << EOF
# Example Repository
deb http://archive.ubuntu.com/ubuntu focal main
deb-src http://archive.ubuntu.com/ubuntu focal main
EOF

3. Writing to Multiple Files Simultaneously

The tee command is named after a T-shaped pipe. It splits the input—sending it to the screen AND to one or more files.

echo "Port 2222" | sudo tee config_backup.conf /etc/ssh/ssh_config.d/custom.conf

This saves the same text to both a local backup and a system directory at the same time.

Summary Table

Try it out: You can try creating a test file in /etc (just don't change existing ones!) to see it in action:
echo "Labby was here" | sudo tee /etc/labby_test.txt