Date: Tue, 24 Jun 1997 08:43:17 -0400 (EDT) From: Tim Vanderhoek <hoek@hwcn.org> To: Steve Howe <un_x@anchorage.net> Cc: freebsd-hackers <hackers@FreeBSD.ORG> Subject: Re: BSD io Message-ID: <Pine.GSO.3.96.970624080450.9455A-100000@james.freenet.hamilton.on.ca> In-Reply-To: <Pine.BSF.3.95q.970623215859.7612A-100000@aak.anchorage.net>
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On Mon, 23 Jun 1997, Steve Howe wrote:
> i remember i asked once how to read in a character mode
> from the keyboard, and while i was, as always, humbled
> by people reaching out to help, i ended up with 3 responses
> with pages of source code each, and no real clear cut answer.
I would guess that the question, or rather, the way it was
worded, implied that you wanted to read directly from the
keyboard. What you probably really wanted to do was to read
input in terms of single characters instead of lines (ie. have
getchar(), etc. return as soon as their is a single character
available, instead of waiting until there is a whole line
avaiable and then returning the first character in the line). To
be even more general, this was probably for the purposes of some
interactive program.
However, when asked "How do I read a single character from the
keyboard?" most people on this list would probably answer,
strictly, how to read a character from the keyboard (in the most
direct manner acceptable). However, when asked "How can I make
my interactive program read single characters of input instead
of whole lines", most would probably answer quickly "Oh! Just
turn off canonical input processing." If they're talkative, they
might even throw in a reference to man 4 termios, or suggest the
use of ncurses to make the program easier to write.
> #include <ncurses.h> and then use cbreak();
> OR
> #include <stdlib.h> and then use system("stty cbreak");
#include <termios.h>
#include <stdio.h>
struct termios old, new;
main(){
tcgetattr (fileno(stdin), &old); new = old;
new &= ~(ICANON|ECHO);
tcsetattr (fileno(stdin), TCSANOW, &new);
/* Do my stuff */
tcsetattr (fileno(stdin), TCSANOW, &old);
}
/* Might want to fiddle MIN and TIME from man 4 termios, but in
practice, it'll not matter much */
> because i find it more efficient to scan a screen for data entries
> / error checking than to write code that deals, in a global sense,
> with each field entered by a cursor.
You don't want to scan the screen directly, you probably just
want to throw what gets entered onscreen into a bunch of separate
strings, and then scan those.
I would guess that some interpreted your quote slightly
differently, though.
Incidentally, ncurses is distributed with a
(completely-documented) libforms which (supposedly) makes it
fairly easy to do that. I can't reccomend it, as I've never used
it, though... (Also, libforms gets stripped from ncurses before
ncurses is distributed with FreeBSD, so you have to grab and
build ncurses yourself. I believe it builds out-of-box.)
> since when does strings work on deleted files?
> others say fsbs (whatever) will do the trick.
Well, I'm using strings on /dev/wd0 right now to try and find any
instances of the word "fuck" on my hdd. su; strings /dev/wd0 |
more. I'm suprised, actually... It's been going for a while and
still hasn't found anything (and all my MS programs are at the
front of the disk! :)... Maybe it's getting screwed-up by
case-sensitivity... <sigh>
--
Outnumbered? Maybe. Outspoken? Never!
tIM...HOEk
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