On Sat, Aug 02, 2003 at 09:20:35AM -0500, Benjamin J. Weiss wrote:
> On Sat, 2 Aug 2003, Buz Davis wrote:
> > I would like a routine to read the keyboard and report the single key
> > pressed, and give me control back without waiting for ENTER to be pressed.
> > ...
>
> Okay, this is going to be an unorthodox answer, but it may get you where
> you need to go...
> <<BIOS read recommended>>
> ...
> Of course, you'd have no portability....
To put it mildly...
You're interacting with the stdio library. Use 'getc'--do "man getc"--for
single-character input. Since terminal input is line buffered, you will
have to make a call to 'setbuf'.
HOWEVER, if you're on Unix/Linux, you'll also have to turn off buffering
in the tty driver. This involves a call to tcgetattr, clearing at
least ICANON, in the c_lflag element, and then a call to tcsetattr.
(This will still show the input character being echoed; you'll have to
separately turn that off.) Man 'termios' for all this.
It sounds uglier than it is--the following really stupid example shows
how to do it. You should--as I don't here--check return values, etc.
(FOR THE NITPICKERS: I REPEAT, IT IS A QUICK AND DIRTY EXAMPLE.
DON'T POST OR MAIL TO TELL ME IT SHOULD BE MORE ROBUST...)
#include <stdio.h>
#include <termios.h>
#include <unistd.h>
int main(int argc, char **argv)
{
char foo;
struct termios krod;
setvbuf(stdin,NULL,_IONBF,0);
tcgetattr(fileno(stdin),&krod);
krod.c_lflag ^= (ICANON|ECHO);
tcsetattr(fileno(stdin),TCSANOW,&krod);
for(;;)
{
foo = getc(stdin);
printf("Got %c\n", foo);
if ( foo == 'x' )
break;
}
}
Cheers,
--
Dave Ihnat
[EMAIL PROTECTED]
--
redhat-list mailing list
unsubscribe mailto:[EMAIL PROTECTED]
https://www.redhat.com/mailman/listinfo/redhat-list
