How to pipe stderr to a command in Bourne or Korn shell

[Leslie Mikesell]

In article <5069:Oct903:10:1390 at kramden.acf.nyu.edu> brnstnd at kramden.acf.nyu.edu (Dan Bernstein) writes:

>But who said there's a tty around? What if Pim wanted to pipe his output
>through yet another command?
>
>  ( exec 5>&1; exec 1>&2; exec 2>&5; foo ) | err-processor
>
>Even you :-) should be able to recognize the swap idiom there. Start
>from basic constructs like this and soon you'll be piping stdout and
>stderr through separate commands. Someday you may even learn to use
>multitee... [grin]

Or FIFO's  (which might even be available on his machine...)

/etc/mknod /tmp/fifo$$ p
err-processor < /tmp/fifo$$ &
command 2>/tmp/fifo$$ | output_processor
rm /tmp/fifo$$

Straightforward enough, and err-processor would not even be required to have
a common parent with the rest of the programs if they have some way
of determining the name to use.

Les Mikesell
  les at chinet.chi.il.us