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From: les@chinet.chi.il.us (Leslie Mikesell)
Newsgroups: comp.unix.questions
Subject: Re: Piping into two processes simultaneously
Keywords: Pipes, two processes
Message-ID: <1990Sep06.150939.18741@chinet.chi.il.us>
Date: 6 Sep 90 15:09:39 GMT
References: <7053@milton.u.washington.edu>
Distribution: usa
Organization: Chinet - Chicago Public Access UNIX
Lines: 19

In article <7053@milton.u.washington.edu> djo7613@hardy.u.washington.edu (Dick O'Connor) writes:
>One of our users phoned me with the question "How do I pipe a stream of
>output into two separate processes at the same time?"  Well, I said tee,
>not thinking, and he said, processes, not files. 

Both tee and processes are perfectly happy with FIFO's if your system
has them.

  /etc/mknod fifo p
  process3 < fifo &
  process1 | tee fifo | process2
  rm fifo

process3 will block until something is written to the fifo and will receive
EOF when the last data has been read and it is no longer open by any process
for writing.

Les Mikesell
  les@chinet.chi.il.us