What does the 'tail -F' command do?

• A. Follow data as it is appended to a file
• B. Find and replace text in a file
• C. Display file permissions
• D. Delete the last line of a file

Answer: (A)

The command 'tail -F' is used primarily in the context of monitoring log files. When you use 'tail -F', it follows the file as new data is appended to it, displaying the most recent additions in real-time. This is particularly useful for system administrators or developers who need to keep track of applications and services, as it allows them to watch log files for real-time updates regarding system activities, errors, or other relevant information.

The '-F' option ensures that if the file is rotated (meaning the current log file is moved or renamed and a new log file is created), 'tail' continues to follow the new file. This behavior is crucial for effective log monitoring since many applications create new log files rather than overwrite existing ones. Therefore, this functionality helps maintain continuous monitoring without requiring additional commands to switch to the new file.