harvey/sys/src/cmd/vt/consctl.c

#include <u.h>
#include <libc.h>
#include <draw.h>
#include "cons.h"

/*
 *  bind a pipe onto consctl and keep reading it to
 *  get changes to console state.
 */
Consstate*
consctl(void)
{
	int i, n, fd, tries;
	char buf[128];
	Consstate *x;
	char *field[10];

	x = segattach(0, "shared", 0, sizeof *x);
	if(x == (void*)-1)
		sysfatal("segattach: %r");

	/* a pipe to simulate consctl */
	if(bind("#|", "/mnt/cons/consctl", MBEFORE) < 0
	|| bind("/mnt/cons/consctl/data1", "/dev/consctl", MREPL) < 0)
		sysfatal("bind consctl: %r");

	/* a pipe to simulate the /dev/cons */
	if(bind("#|", "/mnt/cons/cons", MREPL) < 0
	|| bind("/mnt/cons/cons/data1", "/dev/cons", MREPL) < 0)
		sysfatal("bind cons: %r");

	switch(fork()){
	case -1:
		sysfatal("fork: %r");
	case 0:
		break;
	default:
		return x;
	}

	notify(0);

	for(tries = 0; tries < 100; tries++){
		x->raw = 0;
		x->hold = 0;
		fd = open("/mnt/cons/consctl/data", OREAD);
		if(fd < 0)
			break;
		tries = 0;
		for(;;){
			n = read(fd, buf, sizeof(buf)-1);
			if(n <= 0)
				break;
			buf[n] = 0;
			n = getfields(buf, field, 10, 1, " ");
			for(i = 0; i < n; i++){
				if(strcmp(field[i], "rawon") == 0)
					x->raw = 1;
				else if(strcmp(field[i], "rawoff") == 0)
					x->raw = 0;
				else if(strcmp(field[i], "holdon") == 0)
					x->hold = 1;
				else if(strcmp(field[i], "holdoff") == 0)
					x->hold = 0;
			}
		}
		close(fd);
	}
	exits(0);
	return 0;		/* dummy to keep compiler quiet*/
}