Shell Command for Monitoring File Content in Real-Time
In this blog post, we will explore the tail command, a highly useful tool in the UNIX command line. This command is available on most Unix-like systems, including macOS and Linux.
According to the tail command’s man page, it allows us to display the last part of a file. Here is an example screenshot of the man page for reference.
One common usage of the tail command is to display a specific number of lines from the end of a file using the -n option. For instance, executing the following command will display the last 2 lines of a given file:
1 | tail -n 2 <filename> |
However, my primary use case for tail is to monitor a file for new content. This can be achieved by using the -f option. By executing the following command, tail will continuously monitor the specified file for changes:
1 | tail -f <filename> |
This is particularly handy when dealing with scripts that fetch remote data and append the results to a text file. Using the tail -f command on the results.txt file, I am able to track incoming data in real-time.
In conclusion, the tail command is a versatile tool for monitoring file content. Whether you need to view the last lines of a file or monitor it for changes, tail is a reliable companion in the command line toolkit.
tags: [“Shell”, “UNIX”, “command line”, “tail”, “monitoring”, “real-time”]