The following is a demonstration of the readbytes.d script,


Here the readbytes.d script is run for a few seconds, then Ctrl-C is hit,

   # readbytes.d
   dtrace: description 'sysinfo:::readch ' matched 4 probes
   ^C
   
     mozilla-bin                                                      16
     gnome-smproxy                                                    64
     metacity                                                         64
     dsdm                                                             64
     wnck-applet                                                      64
     xscreensaver                                                     96
     gnome-terminal                                                  900
     ttymon                                                         5952
     Xorg                                                          17544

In this interval the Xorg command has successfully read 17.5 Kb, while
ttymon has read 5952 bytes.