More input on LPD from Patrick for our IESG requested explanation of why IPP
isn't just LPD extended.
Tom
>Return-Path: <jmp-owner at pwg.org>
>Date: Wed, 12 Mar 1997 07:24:10 PST
>From: Patrick Powell <papowell at dickory.sdsu.edu>
>To: jkm at underscore.com, rbergma at dpc.com>Subject: Re: JMP> LPD Job submission mapping
>Cc: jmp at pwg.org>Sender: jmp-owner at pwg.org>># The LPD protocol (aka RFC 1179) was NOT designed in a vacuum. It was
># designed as part and parcel of the LPD daemon environment; that environment
># expected to FIRST spool all components of the submitted job (one or more
># data files, followed by one control file). So, if you have the luxury
># of spooling all these components, then of course you can "reverse the order".
>>Umm... you are going to hate this, but actually LPR came first, RFC1179
>was simply documenting LPR. This is the same thing as RIP - RIP was
>first, then the RIP RFC came much later; note that the RFC had some
>'do this as I say, not as I do' type things in it.
>># In the category of "Fun Things to Know and Forget": in our travels,
># only OS/2 2.1 sends the control file before the data file(s). I
>wonder # how many LPD daemon systems mess up as a result of this...
>>Ummm... I think you mean 'the broken vendor implementation of OS/2's
>print spooler'... There are 2nd party spoolers that do it in EITHER
>order, selectable by a run time switch.
>>Note that the BSD based LPR implementations usually send control files
>first, the ones supplied with SYS III, send data files first, and the
>SYS VR4 seem to do what they damn well please from release to release.
>In the PC world, I have seen both - there is a drop in LPR client for
>most Windows 3.1 WINSOCK support packages, and I have seen both data
>first or job first from different packages.
>>I have also noted that some printer manufacturers, when the implement
>LPD servers in their systems, IGNORE the control file and use
>'autosense' methods to determine what the file contents are.
>I remember fighting with a XXX (censored) printer, and trying to print
>a students 'malformed postscript' file so I could take it away and look
>at it and the printer kept locking up with 'postscript stack... '
>messages printed on it.
>>Hey! Why should we be surprised? Given so much broken software out
>there, most people try to be as accomodating as possible in what they
>accept, and as restricted as possible in what they send.
>>Patrick Powell
>># ...jay
>>