#include <rtl.h>#include <rtl_fifo.h>#include <time.h>#include <rtl_sched.h>#include <rtl_sync.h>#include <pthread.h>#include <unistd.h>#include <stdarg.h>//#include <stdarg.h>void user_printf(const char *fmt,...);int OUT;#define eprint rtl_printf  // so I could debug this code in user space#define BUFSIZE 500char  buf[BUFSIZE];int init_module(void){		rtf_destroy(0);	if ( (OUT = open("/dev/rtf0",O_WRONLY | O_NONBLOCK | O_CREAT )) < 0)	{		rtl_printf("Example cannot open fifo\n");		rtl_printf("Error number is %d\n",errno);		return -1;	}	user_printf("Test from init code\n"); //DEBUG	return 0;}void cleanup_module(void){ 	close(OUT);}static int fixcopy(int space, char *dest, void *v,int sz){	char *c = (char *)v;	if(sz > space){		eprint("RTL error: user_printf out of space\n");		return -1;       	}	else{		while(sz > 0){*dest++ = *c++; sz--;}	}	return 0;}static int safecopy(int space, char *dest, const char *src){	int len = strlen(src)+1;	if(len > space){		eprint("RTL error: Can't user_printf very long strings\n");		return -1;       	}	strncpy(dest,src,len);	return len;}void user_printf(const char *fmt,...){       	int len,i,d,l;       	char *s;       	double f;       	va_list ap;       	/* dump the character string */       	if ( (len = safecopy(BUFSIZE, buf,fmt)) < 0)return;       	/* then copy the characters */       	va_start(ap, fmt);       	for(i=0; i < strlen(fmt); i++){	       	if(fmt[i] == '%') switch(fmt[i+1]) {		       	case 's':           /* string */			       	s = va_arg(ap, char *);			       	l = safecopy(BUFSIZE -len, buf+len,s);			       	if(l<0)return;			       	len += l;			       	break;		       	case 'd':           /* int */		       	case 'c':           /* char is in an int */			       	d = va_arg(ap, int);			       	if(fixcopy(BUFSIZE-len, buf+len, &d,sizeof(d)))					return;			       	len += sizeof(d);			       	break;		       	case 'f':           /* double */			       	f = va_arg(ap, double);			       	if(fixcopy(BUFSIZE-len, buf+len, &f,sizeof(f)))					return;			       	len += sizeof(f);			       	break;	       	}	}	rtl_printf("user printf writes %d bytes\n",len);//DEBUG	write(OUT,&len,sizeof(len));	write(OUT,buf,len);}