Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!rutgers!ames!lll-tis!ptsfa!ihnp4!inuxc!iuvax!bsu-cs!dhesi
From: dhesi@bsu-cs.UUCP (Rahul Dhesi)
Newsgroups: comp.unix.wizards
Subject: Re: /dev/stdin for 4.3?
Message-ID: <684@bsu-cs.UUCP>
Date: Thu, 21-May-87 17:04:19 EDT
Article-I.D.: bsu-cs.684
Posted: Thu May 21 17:04:19 1987
Date-Received: Sat, 23-May-87 14:23:05 EDT
References: <7359@brl-adm.ARPA> <983@bobkat.UUCP> <5872@brl-smoke.ARPA>
Reply-To: dhesi@bsu-cs.UUCP (Rahul Dhesi)
Organization: CS Dept, Ball St U, Muncie, Indiana
Lines: 19

In article <5872@brl-smoke.ARPA> gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>) 
explains the need for a /dev/stdin thus:
>           ....any place where the code is set up to deal with a filename
>but you might prefer to use the output end of a pipe (for example).
>	$ cmd | sort | troff header /dev/stdin trailer
>Some commands give special meaning to "-" as a filename, but it is much
>better to provide a general facility.

I see a potential problem here.  Programs that won't let you read from
standard input will frequently attempt to do seeks within the input
file.  So to anybody planning to implement /dev/stdin, I suggest adding
a buffering facility that allows seeks to within the buffered area.
Make the buffer size configurable at boot time if possible or better
still, let it be configurable for individual users when they log in.
(Can UNIX devices use non-kernel buffers dynamically?  I have no idea.)

In fact, pipes ought really to be extended to do dynamic buffering.
-- 
Rahul Dhesi         UUCP:  {ihnp4,seismo}!{iuvax,pur-ee}!bsu-cs!dhesi