#include<fcntl.h>
#include<sys/types.h>
#include<sys/stat.h>
#define RWBUF_DEV "/dev/rwbuf"
#define RWBUF_CLEAR 0x909090

int main(){
 char yourmsg[18] = "Get it!\n";
 char tmp[10];
 int h= open(RWBUF_DEV,O_RDONLY);
 int n=write(h,tmp,sizeof(tmp));
 close(h);
 h = open(RWBUF_DEV,O_RDONLY);
 n = ioctl(h,RWBUF_CLEAR,0);
 close(h);
 h= open(RWBUF_DEV,O_RDONLY);
 n= read(h,yourmsg,sizeof(yourmsg)+1);

 close(h);
}