#include <stdio.h>
#include <fcntl.h>#include <sys/types.h>#include <sys/stat.h>
char buf[128];
int main(){	int dev_test;
	dev_test=open("/dev/mydevice",O_RDWR);	if(dev_test==-1)	{			printf("\nCan't open the device!\n");		return (-1);	}	printf("\nmy_device opend!");	printf("\nreading...\n");	read(dev_test,buf,128);	printf(buf);	printf("writing...\n");	write(dev_test,"test",4);	printf("my_device closed!\n");	close(dev_test);	return 0;}