Comprehensive List of Tail Commands with Descriptions

Comprehensive List of Tail Commands with Descriptions - Printable Version

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Comprehensive List of Tail Commands with Descriptions - Sneakyone - 09-03-2024

Comprehensive List of Tail Commands with Descriptions

**tail** is a command-line utility used to display the last few lines of a file or stream. It is commonly used for viewing the end of log files and for monitoring files as they are updated in real-time. Below is a detailed list of tail commands, along with descriptions and examples.

1. Displaying the Last 10 Lines of a File (Default)
Description: By default, the tail command displays the last 10 lines of a specified file.

Code:
tail [file]

Example: To display the last 10 lines of `example.log`:

Code:
tail example.log

2. Displaying a Specific Number of Lines
Description: Displays a specified number of lines from the end of a file.

Code:
tail -n [number_of_lines] [file]

Example: To display the last 20 lines of `example.log`:

Code:
tail -n 20 example.log

3. Displaying Lines from a Specific Byte Offset
Description: Starts displaying lines from a specific byte offset from the end of the file.

Code:
tail -c [byte_offset] [file]

Example: To display the last 100 bytes of `example.log`:

Code:
tail -c 100 example.log

4. Displaying Lines from a Specific Line Number
Description: Displays lines starting from a specific line number.

Code:
tail -n +[line_number] [file]

Example: To display lines starting from line 50 of `example.log`:

Code:
tail -n +50 example.log

5. Following a File in Real-Time
Description: Continuously monitors a file and displays new lines as they are added.

Code:
tail -f [file]

Example: To follow `example.log` and display new entries as they are added:

Code:
tail -f example.log

6. Following Multiple Files
Description: Monitors multiple files and displays new lines from all of them as they are added.

Code:
tail -f [file1] [file2] ...

Example: To follow `example1.log` and `example2.log` simultaneously:

Code:
tail -f example1.log example2.log

7. Following a File and Terminating After a Certain Condition
Description: Monitors a file and stops after a certain number of lines have been output.

Code:
tail -f [file] | head -n [number_of_lines]

Example: To follow `example.log` and stop after 10 new lines have been printed:

Code:
tail -f example.log | head -n 10

8. Following a File with Retry Option
Description: Continuously monitors a file, retrying if the file is not found (useful for log files that may not exist at the start).

Code:
tail -f --retry [file]

Example: To follow `example.log` with retry if the file is initially missing:

Code:
tail -f --retry example.log

9. Suppressing Headers When Following Multiple Files
Description: Suppresses the header that shows the filename when following multiple files.

Code:
tail -f --quiet [file1] [file2] ...

Example: To follow `example1.log` and `example2.log` without showing file headers:

Code:
tail -f --quiet example1.log example2.log

10. Displaying Help Information
Description: Displays help information for the tail command, listing all available options and their descriptions.

Code:
tail --help

Example: To display help information for tail:

Code:
tail --help

Conclusion

The **tail** command is a powerful and versatile tool for monitoring the end of files, making it an essential utility for system administrators, developers, and anyone who needs to keep an eye on log files. By mastering these commands, you can efficiently view and monitor file contents in real-time, ensuring effective file management and troubleshooting.

Happy Monitoring!