tail Command Linux Examples

Last Updated on December 11, 2023 by Abhishek Sharma

The tail command in Linux is a powerful tool designed to display the end of a text file or a stream of data. It’s a fundamental utility used by system administrators, developers, and users to extract specific information or monitor real-time updates within files. This command is versatile, offering various options to suit different needs, such as viewing the last few lines of a file, continuously monitoring changes in logs, or even displaying newly appended data in a file.

Understanding how to effectively use tail is crucial for efficiently managing and analyzing log files, tracking ongoing processes, or extracting pertinent information from files. In this article, we’ll explore various examples showcasing the practical applications of the tail command in Linux, catering to different scenarios and illustrating its flexibility in handling file contents and streams.

What is Tail Command in Linux?

The tail command in Linux is a command-line utility used to display the end of a text file or stream of data. It is primarily employed to view the last few lines of a file or to continuously monitor updates in a file as new data is appended to it. The tail command is particularly useful for observing log files in real-time, tracking changes, and extracting specific information from the end of files without needing to load and display the entire contents.

By default, tail displays the last 10 lines of a file, but it offers various options (-n, -f, -c, etc.) to customize the output based on the number of lines, bytes, or even following updates in real-time. This versatility makes tail a crucial tool for system administrators, developers, and users working with textual data or managing system logs within the Linux environment.

Examples of tail Command in Linux

Here are some examples demonstrating the usage of the tail command in Linux:

1. Display last 10 lines of a file:

tail 

This command will display the last 10 lines of the specified file.

2. Display specific number of lines from the end of a file:

tail -n 15 

This command will display the last 15 lines of the specified file. Replace 15 with the desired number of lines.

3. Display contents of multiple files simultaneously:

tail file1.txt file2.txt

You can pass multiple filenames as arguments to tail to view the last few lines of each file.

4. Monitor changes in a file in real-time:

tail -f 

The -f option (-f for "follow") allows continuous monitoring of a file, displaying new content as it’s appended. This is commonly used for real-time log monitoring.

5. Display the last N bytes of a file:

tail -c 1000 

This command will display the last 1000 bytes of the specified file. Replace 1000 with the desired number of bytes.

6. Combine tail with other commands using pipes:

some_command | tail -n 5

This command takes the output of some_command and displays the last 5 lines of that output.

7. Continuously monitor and track changes in multiple files:

tail -f file1.log file2.log

You can monitor updates in multiple files simultaneously by specifying each file separated by a space.

These examples showcase the flexibility of the tail command in Linux, allowing users to extract specific information from files, monitor ongoing processes, and efficiently track changes in real-time.

Conclusion:
The tail command remains an indispensable tool in the Linux ecosystem, offering simplicity and versatility in handling file content. From monitoring logs in real-time to extracting specific data from files, its functionalities aid in debugging, tracking changes, and extracting essential information swiftly and effectively.

By mastering the diverse options and functionalities of tail, users can streamline their tasks, troubleshoot issues efficiently, and access crucial information swiftly within the Linux environment. Whether it’s monitoring live updates or extracting specific data, tail stands as a reliable ally for users navigating through vast amounts of textual data.

FAQs (Frequently Asked Questions) Related to tail Command in Linux:

Here are some FAQs related to tail commands in Linux.

Q1: How does tail differ from head in Linux?
tail and head are both command-line utilities in Linux used for viewing file content. However, they differ in their functionality. tail displays the last part of a file or stream, while head displays the beginning (first lines) of a file or stream.

Q2: Can tail command be used to monitor log files in real-time?
Yes, tail is commonly used to monitor log files in real-time. By using the -f option (tail -f ), it allows continuous tracking and updates of the file, displaying new content as it’s appended.

Q3: How can I display a specific number of lines from the end of a file using tail?
You can specify the number of lines to display from the end of a file using the -n option followed by the number of lines. For instance, tail -n 10 displays the last 10 lines of the file.

Q4: Is it possible to use tail with multiple files simultaneously?
Yes, tail supports monitoring multiple files simultaneously. You can pass multiple filenames as arguments (tail ) to view the last few lines of each file or use wildcard characters (tail *.txt) to monitor multiple files matching a specific pattern.