Run the specified command repeatedly (by default, every 2 seconds) and display the output so you can watch it change over time. The command and any options are passed to sh -c, so you may need to use quotes to get correct results.
Highlight changes between iterations. If cumulative is specified, the highlighting remains on the screen throughout, giving a cumulative picture of the changes.
Display help message and exit.
Run the command every secs seconds.
Print version information and exit.