ref: a035fa013e92d436806dac855c4dd772292e4c20
dir: /sys/src/cmd/aux/vga/error.c/
#include <u.h>
#include <libc.h>
#include <bio.h>
#include "pci.h"
#include "vga.h"
int vflag, Vflag;
void
error(char* format, ...)
{
	char buf[512], *out;
	va_list arg;
	int n;
	sequencer(0, 1);
	n = sprint(buf, "%s: ", argv0);
	va_start(arg, format);
	out = vseprint(buf+n, buf+sizeof(buf)-n, format, arg);
	va_end(arg);
	if(vflag)
		Bprint(&stdout, "%s", buf+n);
	Bflush(&stdout);
	write(2, buf, out-buf);
	exits("error");
}
void
trace(char* format, ...)
{
	char buf[512];
	va_list arg;
	if(vflag || Vflag){
		if(curprintindex){
			curprintindex = 0;
			Bprint(&stdout, "\n");
		}
		va_start(arg, format);
		vseprint(buf, buf+sizeof(buf), format, arg);
		va_end(arg);
		Bprint(&stdout, "%s", buf);
		if(Vflag)
			print("%s", buf);
	}
}