Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!mcvax!cernvax!ethz!ethz-inf!wyle
From: wyle@inf.ethz.ch (Mitchell Wyle)
Newsgroups: comp.unix.wizards
Subject: Examples of multiple stream shell scripts
Keywords: multiple streams, parallel pipes
Message-ID: <258@ethz-inf.UUCP>
Date: 2 Jun 89 14:01:00 GMT
Reply-To: wyle@inf.ethz.ch
Organization: Departement fuer Informatik, ETH Zuerich
Lines: 27

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@inf.ethz.ch 
ETH Zentrum / 8092 Zurich, Switzerland    +41 1 256 5237