The
utility examines the list of current processes to find a specified process
and all its descendants.
A process may be specified either by name or by process ID.
If no arguments are given,
displays a list of the whole process tree.
For each process specified on the command line,
outputs a line containing the process ID, the command name, and the PIDs
of all the descendants (and their descendants, etc.).
When invoked as
rkill
this utility does not display information about the processes, but sends
them all a signal instead.
If not specified on the command line, a terminate (SIGTERM) signal is
sent.
When invoked as
rrenice
this utility does not display information about the processes, but attempts
to set their nice value instead.