From: segaloco via TUHS <tuhs@tuhs.org>
To: The Eunuchs Hysterical Society <tuhs@tuhs.org>
Subject: [TUHS] Stdin Redirect in Cu History/Alternatives?
Date: Sat, 10 Dec 2022 19:38:45 +0000 [thread overview]
Message-ID: <9QJtlCA0hfDuNuwOqorx1uC2eSGOiIBu0hgsVAaKclEWUw4Gi9PAjJoZgcOF7W6rRCw4XqM3wBZMavgF_HEH4GR2WuczKF5w_tZAjAXgzlE=@protonmail.com> (raw)
Good morning all. I've been doing some historical research on the UUCP cu utility this morning and have come across a little discrepancy between the various UNIX streams I was wondering if someone could illuminate.
So cu as of V7 supported the ~$ escape, a means of calling a local procedure and emitting stdout over the TTY line to the remote machine, all fine and good for packaging a character stream to emit. However, what I'm not finding in that age of documentation is any means of requesting std*in* from the TTY line as input to a local procedure (in essence running a text filter or handshake-driven protocols over cu). The context in which I'm researching this is integrating cu into my bare-metal SBC programming using XMODEM so I can rest a little easier my process is based on tools I'll probably find in most places.
So old fashioned Mike Lesk-era cu only seems to do stdout redirect, but no stdin. I did some further digging and it looks like different UUCP implementations cracked this nut with different escapes, with BSD eventually going with ~C and Taylor UUCP opting for ~+. Checking the current illumos manual pages (for a SVR4-ish example) doesn't turn up any command for this. This is indicative of there never being an agreed-upon mechanism for doing this, although I could see this being a very useful mechanism.
What I'm curious about is if the lack of a bi-directional redirect in early cu is reflective of a lack of need for that sort of functionality at the time or that matters such as that were handled through a different mechanism. One thought I did have is that there wasn't file locking at the time (right?) and so theoretically nothing would prevent one from using a cu session on one terminal to send interactive commands and then a second using fd redirects in the shell to run filters/protocols separately of the interactive stream.
- Matt G.
next reply other threads:[~2022-12-10 19:39 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-10 19:38 segaloco via TUHS [this message]
2022-12-11 0:22 ` [TUHS] " Clem Cole
2022-12-11 2:37 ` segaloco via TUHS
2022-12-11 13:59 ` Michael Kjörling
2022-12-11 14:28 ` Steve Nickolas
2022-12-11 15:04 ` Dan Cross
2022-12-13 1:54 ` Larry McVoy
2022-12-11 17:18 ` Adam Thornton
2022-12-11 18:54 ` Michael Kjörling
2022-12-11 19:55 ` Dave Horsfall
2022-12-11 20:03 ` Larry McVoy
2022-12-11 23:22 ` segaloco via TUHS
2022-12-12 2:15 ` [TUHS] Clever code (was " Bakul Shah
2022-12-12 2:44 ` [TUHS] " Steve Nickolas
2022-12-12 3:09 ` Andrew Warkentin
2022-12-12 3:34 ` Larry McVoy
2022-12-12 5:00 ` Kevin Bowling
2022-12-12 5:26 ` Andrew Warkentin
2022-12-12 15:02 ` Larry McVoy
2022-12-12 15:29 ` Clem Cole
2022-12-12 15:39 ` Dan Cross
2022-12-12 16:04 ` Larry McVoy
2022-12-12 16:26 ` Clem Cole
2022-12-12 22:20 ` Liam Proven
2022-12-12 23:10 ` segaloco via TUHS
2022-12-12 23:24 ` Larry McVoy
2022-12-13 2:00 ` Andrew Warkentin
2022-12-13 13:37 ` Larry McVoy
2022-12-13 23:00 ` Andrew Warkentin
2022-12-14 1:05 ` Larry McVoy
2022-12-14 1:40 ` segaloco via TUHS
2022-12-14 6:32 ` Rich Morin
2022-12-14 2:01 ` Andrew Warkentin
2022-12-14 7:49 ` arnold
2022-12-14 11:54 ` Brad Spencer
2022-12-14 12:08 ` [TUHS] Re: (TUHS -> COFF?) Re: Clever code Michael Kjörling
2022-12-14 15:14 ` [TUHS] Microware's OS-9 (was: Clever code) G. Branden Robinson
2022-12-14 22:41 ` [TUHS] " John Cowan
2022-12-14 9:46 ` [TUHS] Re: Clever code (was Re: Re: Stdin Redirect in Cu History/Alternatives? Harald Arnesen
2022-12-15 18:33 ` Liam Proven
2022-12-16 10:42 ` Harald Arnesen
2022-12-18 14:05 ` Liam Proven
2022-12-18 15:08 ` Stuff Received
2022-12-19 11:47 ` Liam Proven
2022-12-20 8:30 ` Andrew Warkentin
2022-12-20 11:57 ` Liam Proven
2022-12-15 0:29 ` Bakul Shah
2022-12-15 2:54 ` Larry McVoy
2022-12-15 5:36 ` Bakul Shah
2022-12-15 14:02 ` Dan Cross
2022-12-15 14:06 ` Larry McVoy
2022-12-15 14:18 ` Dan Cross
2022-12-15 14:02 ` Larry McVoy
2022-12-15 8:01 ` Andrew Warkentin
2022-12-12 9:48 ` [TUHS] Re: Clever code Michael Kjörling
2022-12-12 21:34 ` [TUHS] Re: Stdin Redirect in Cu History/Alternatives? Dave Horsfall
2022-12-12 21:46 ` Chet Ramey
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