The watch command allows you to continuously watch a command.
To use it, start the command with the word watch and any options that would
be applicable to watch.
Options for the command that watch is being combined with go after that
command.
One option that can be used with watch is the -n flag, which allows you to
specify a time (in seconds) that the command should be renewed with.
As an example, the following command will watch the
rsync or qstat command for a
specific user, updating it every 5 seconds instead of the default 2 seconds.
$ watch -n 5 qstat -u euid123
Because the command is continuously updating, the only ways to end it are with rsync or cntrl+c or closing the terminal.