How to Use Tail Command in Linux: Syntax and Examples

The tail command in Linux shows the last part of a file, usually the last 10 lines by default. You can use options like -n to specify the number of lines or -f to follow a file as it grows in real time.

Syntax

The basic syntax of the tail command is:

• tail [options] [file]

Where:

• options modify the behavior, like how many lines to show or to follow the file.
• file is the name of the file you want to read the end of.

bash

tail [options] [file]

Example

This example shows how to display the last 5 lines of a file named logfile.txt and then follow the file to see new lines as they are added.

bash

tail -n 5 logfile.txt

# To follow the file in real time
 tail -f logfile.txt

Output

Line 96: Error detected
Line 97: Restarting service
Line 98: Service started
Line 99: Connection established
Line 100: Listening on port 8080

# (When running tail -f, new lines will appear here as they are added)

Common Pitfalls

Some common mistakes when using tail include:

• Forgetting to specify the number of lines with -n and expecting a different default.
• Using tail -f without knowing how to stop it (use Ctrl+C to exit).
• Trying to tail a file that does not exist, which will cause an error.

bash

tail -n logfile.txt  # Wrong: missing number after -n

# Correct usage:
tail -n 10 logfile.txt

Output

tail: option requires an argument -- 'n'
Try 'tail --help' for more information.

Quick Reference

Option	Description
-n	Show the last lines of the file
-f	Follow the file as it grows, showing new lines in real time
-c	Show the last bytes of the file
--help	Display help information about tail command

Key Takeaways

Use tail -n to specify how many lines to display from the end of a file.

Use tail -f to watch a file update live, useful for logs.

Always check the file exists before using tail to avoid errors.

Stop a running tail -f with Ctrl+C.

The default output of tail is the last 10 lines if no options are given.