9fans - fans of the OS Plan 9 from Bell Labs
 help / color / mirror / Atom feed
From: "Joel Salomon" <joelcsalomon@gmail.com>
To: "Fans of the OS Plan 9 from Bell Labs" <9fans@cse.psu.edu>
Subject: [9fans] Implementing cooked mode
Date: Wed, 20 Dec 2006 19:54:58 -0500	[thread overview]
Message-ID: <7871fcf50612201654u2bf12d6j7a8291991e4ef991@mail.gmail.com> (raw)

If a program has the console in raw mode, can it erase characters or
words that it has echoed to the screen?

Context is a homework assignment to implement cooked mode in user
space.  The code in /sys/src/cmd/rio/wind.c looks to be a start, but I
don't see how to remove characters from the screen.  I suppose I could
use string() in libdraw and draw the string graphically rather than
echoing.  Rio's wind.c and acme's text.c both handle the various
control characters, but they aren't pretending to write to the
console.

Nemo's book has a similar assignment, so it seems to be doable; I just
haven't found how in the manual.

Failing that, are there printable glyphs shown if control characters
are write()n to the console?

--Joel


             reply	other threads:[~2006-12-21  0:54 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-12-21  0:54 Joel Salomon [this message]
2006-12-21  1:08 ` Russ Cox
2006-12-21  1:47   ` Russ Cox
2006-12-21 12:50     ` Brantley Coile
2006-12-21  2:27 ` [9fans] " Joel Salomon
2006-12-21  4:01   ` Russ Cox
2006-12-21  1:37 [9fans] " erik quanstrom
2007-02-15 17:44 ` Harri Haataja

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=7871fcf50612201654u2bf12d6j7a8291991e4ef991@mail.gmail.com \
    --to=joelcsalomon@gmail.com \
    --cc=9fans@cse.psu.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).