The DUP System

Note that the label at the beginning of each DUP instruction does not have to correspond to the name of the process at all. Also, file-descriptors don't have to be unique in the system. If you want to do the equivalent of

cat - | grep Hello | tr wW | grep World

in DUP, you could use:

g1@localhost[DUP:0|0,1|tr:0] $ grep Hello ;
tr@localhost[1|g2:0] $ tr wW ;
g2@localhost[1|DUP:1] $ grep World ;

The same also applies to stages with multiple input and output streams.