ts_ret.c

来自「上学的时候写的蓝牙触控板程序」· C语言 代码 · 共 95 行

#define _GNU_SOURCE
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/poll.h>
#include <sys/ioctl.h>


static volatile sig_atomic_t __io_canceled = 0;

static void sig_hup(int sig)
{
}

static void sig_term(int sig)
{
	__io_canceled = 1;
}

typedef struct{
  unsigned short pressure;
  unsigned short x;
  unsigned short y;
  unsigned short pad;
}TS_RET;

void Print_Ts_ret (const TS_RET pbuf);

int main ( int argc, char* argv[] )
{
	TS_RET buf = {0};
	struct sigaction sa;
	struct pollfd p;
	sigset_t sigs;
	int i, ts, len;

	ts = open ("/dev/touchscreen/0raw", O_RDONLY|O_NDELAY);
	if ( ts < 0 )
	  {
	    fprintf ( stderr, "Can not open Touchscreen\n" );
	    exit (1);
	  }
	
	memset(&sa, 0, sizeof(sa));
	sa.sa_flags   = SA_NOCLDSTOP;
	sa.sa_handler = SIG_IGN;
	sigaction(SIGCHLD, &sa, NULL);
	sigaction(SIGPIPE, &sa, NULL);

	sa.sa_handler = sig_term;
	sigaction(SIGTERM, &sa, NULL);
	sigaction(SIGINT,  &sa, NULL);

	sa.sa_handler = sig_hup;
	sigaction(SIGHUP, &sa, NULL);

	sigfillset(&sigs);
	sigdelset(&sigs, SIGCHLD);
	sigdelset(&sigs, SIGPIPE);
	sigdelset(&sigs, SIGTERM);
	sigdelset(&sigs, SIGINT);
	sigdelset(&sigs, SIGHUP);

	p.fd = ts;
	p.events = POLLIN | POLLERR | POLLHUP;

	while (!__io_canceled) {
		p.revents = 0;
		if (poll(&p, 1, 500) < 1)
			continue;

		len = read( ts, &buf, sizeof(buf));
		if (len < 0)
			break;
		Print_Ts_ret ( buf );
	}

	close(ts);

	return 0;
}

void Print_Ts_ret ( const TS_RET pbuf)
{
  printf ("--------------\n");
  printf ("Pressure:   %d\n", pbuf.pressure );
  printf ("Location X: %d\n", pbuf.x );
  printf ("Location Y: %d\n", pbuf.y );
  printf ("Pad status: %d\n", pbuf.pad );
}