The DUP System

The most useful general-purpose DUP stages are:

fanout

Broadcast input to any number of outputs

deal

Write inputs to any number of outputs in round-robin fashion

faninany

Read any number of inputs in any order, forward to standard output

gather

Read any number of inputs in round-robin fashion, forward to standard output

All of these stages have the option to run in line-mode or in record-mode (block-oriented). For details about how errors are managed the man pages should be consulted.

Finally, the dup command itself can be used as a stage, which can be interesting when a component written in DUP is to be used within a larger DUP application. In this case, it is often convenient to invoke dup with the -c option in order to keep standard input and standard output available to be used for input and output streams.