Examples of multiple stream shell scripts

[Mitchell Wyle]

I have twice (for two different projects) tried unsuccessfully to
process two streams in parallel in Bourne shell scripts.  I'd
appreciate RTFM references, relevant examples and your help.

Consider the following pipleline:


               cos2
             /     \
            /       \
cos1 < file           cos4 |  cos5 > report 
            \       /       /
             \     /       /
               cos3 -------


where the output of cos2 and cos3 are join(1)ed to form the input to
cos4; the output of cos4 and cos3 are joined again for cos5.

Can tee(1) send output to multiple *streams* (not files)?  
What about named pipes?

Thanks for your help.  -Mitch
-- 
-Mitchell F. Wyle
Institut fuer Informationssysteme         wyle at inf.ethz.ch 
ETH Zentrum / 8092 Zurich, Switzerland    +41 1 256 5237