Article View: comp.std.unix
Article #631Re: File system name space (/dev/fd)
From: Kristoffer Eriksson
Date: Tue, 30 Oct 1990 09:01
Date: Tue, 30 Oct 1990 09:01
22 lines
1596 bytes
1596 bytes
Submitted-by: ske@pkmab.se (Kristoffer Eriksson)
In article <14102@cs.utexas.edu> addw@phcomp.co.uk (Alain Williams) writes:
>> join <(prog1) <(prog2) > joined-output-of-progs-1-and-2
>Anyway, the above wouldn't work with a straight /dev/fd as has been talked about
>here recently. Why ? The trouble is that if /dev/fd contains files with
>names "0", "1", ... "19", the programs prog1 & prog2 would both have a file
>/dev/fd/1 as their stdout, join would see another /dev/fd/1.
That's not how you do it. Prog1 and prog2 just output to their standard
outputs, as they always do, and the shell sets up pipes from prog1 and prog2
to join. The /dev/fd names for these pipes, as seen by join, are then passed
as argv[] parameters to join, to make it read them. Prog1 and prog2 never
see them.
--
Kristoffer Eriksson, Peridot Konsult AB, Hagagatan 6, S-703 40 Oerebro, Sweden
Phone: +46 19-13 03 60 ! e-mail: ske@pkmab.se
Fax: +46 19-11 51 03 ! or ...!{uunet,mcsun}!sunic.sunet.se!kullmar!pkmab!ske
Volume-Number: Volume 22, Number 12
Technical Details
Message-ID:
<14161@cs.utexas.edu>Path:
arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!jsqReferences:
<14012@cs.utexas.edu> <14014@cs.utexas.edu> <14102@cs.utexas.edu>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!jsq From: ske@pkmab.se (Kristoffer Eriksson) Newsgroups: comp.std.unix Subject: Re: File system name space (/dev/fd) Message-ID: <14161@cs.utexas.edu> Date: 30 Oct 90 09:01:59 GMT References: <14012@cs.utexas.edu> <14014@cs.utexas.edu> <14102@cs.utexas.edu> Sender: jsq@cs.utexas.edu Organization: Peridot Konsult i Mellansverige AB, Oerebro, Sweden Lines: 22 Approved: jsq@cs.utexas.edu (Moderator, John S. Quarterman) X-Submissions: std-unix@uunet.uu.net