shutdown() - shutdown the driver


void shutdown( int how );


This function shuts down the driver in a controlled fashion (as opposed
to how a crash would shut it down).  The 'how' argument  specifes  what
integer  value that driver should pass to exit().  The convention is to
pass 'how' as -1 when the script that restarts the driver should die as
well.   Thus a reboot command would use shutdown() while a halt command
would use shutdown(-1).  The script must explicitly  check  the  return
value  to  see  if  it is -1 if you wish to use this convention.  Obvi‐
ously, shutdown() is a sensitive function and should  be  secured.   As
with  exec(),  the  way to make it secure is to add a simul_efun of the
same name which does the appropriate security checks.  Be sure  to  set
valid_override(4) up (in master.c) to protect against efun::shutdown().