Today, we shall talk about one of the most frequently used command in Linux.

TAIL

The command is used to print last 10 lines of a file.

tail -f is used to print the last 10 lines plus it keeps on reading the file if a new data is added to the file.

tail -f can be used if a log is currently being updated. 

But then what is the use of tailf?

tailf is similar to tail -f except one difference that tailf does access the file if the file is not being updated or not growing.

tailf is extremely useful for monitoring log files on a laptop when logging is infrequent and the user desires that the hard disk spin down to conserve  battery life.

It means that tail -f will keep on accessing/reading the file even if its not growing.

This has the side effect of not updating the access time for the file, so a filesystem flush does not occur periodically when no log activity is happening.

The tailf command is part of the util-linux-ng package

So now that you know about tailf, start using tailf instead of tail -f to conserve energy :).