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.