Something

$ tclsh
% load ../tcl/hal.so
% hal loadrt not
Component 'not' ready
Program '/home/jepler/emc2.head/bin/rtapi_app' started
Realtime module 'not' loaded
% hal show pin
Component Pins:
Owner  Type  Dir     Value      Name
 32769    bit   IN          FALSE  not.0.in
 32769    bit   OUT         FALSE  not.0.out