2. Command function: used to display the contents at the end of the specified file. If no file is specified, it will be treated as input information. Usually used to view log files.

3. Command parameters: -f cyclic reading -q does not display processing information -v displays detailed processing information -c displays the number of bytes -n displays the number of rows-pid=Pid is used together with -f, indicating that it ends after the process ID and PID die. -q, -quiet, -silent never outputs the header of a given file name -s, -s,-sleep-interval=S =

4. Use example: example 1: Display the contents at the end of the file command: tail-n5log2014.logOutput: # tail-n5log2014.log2010.