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Date: Mon, 14 Mar 2005 22:05:34 -0500
From: Matt Kory <uber.caulker@gmail.com>
To: freebsd-hackers@freebsd.org
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Subject: poll or select for ppi?
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Is it possible to use poll or select to detect a change in the status
bits of the parallel port?  I tried something like this, and took bits
5 and 6 of the status register low and nothing seemed to happen.  Is
what I am trying to do even possible, or I am supposed to take a
certain bit low to cause a read event?  Any help is appreciated.

int ppi_fd;
char port[] = "/dev/ppi0";
ppi_fd = open(port, O_RDWR);

fd_set rfds;
struct timeval tv;
tv.tv_sec = 0;
tv.tv_usec = 100000;

while(1) {
FD_ZERO( &rfds );
FD_SET( ppi_fd, &rfds );
if ( select(1, &rfds, NULL, NULL, &tv) ) {
 printf("hi\n");
 }
}