#include "stdio.h"
#include "unistd.h"
#include "sys/types.h"
#include "sys/stat.h"
#include "fcntl.h"
#include "stdlib.h"
#include "string.h"

int main(int argc, char *argv[])
{
	int fd;
	char buf[32];
	char write_buf[] = "write_success";
	char filename[32] = "/dev/test";
	fd = open(filename, O_RDWR);
	if(fd < 0){
		printf("file %s open failed!\r\n", argv[1]);
		return -1;
	}
	read(fd,buf,sizeof(buf));
	write(fd,write_buf,sizeof(write_buf));
	printf("%s\n",buf);
	printf("open *******\n");	
	close(fd);
	return 0;
}