#include
#include
#include
#include
#include
#include


#include
#include
using namespace std;
int fd;
int fw;
int main（int argc, char *argv[]）{


fd = open（"in1.txt", O_CREAT | O_TRUNC | O_RDWR, 0644）;
if（fd == -1 ）{
cout << "error";}
fw = open（"out1.txt", O_CREAT | O_TRUNC | O_WRONLY,0644）;
if（fw == -1）{
cout << "error_2";}
char a[20] = "1234";
write（fd,a,sizeof（a））;


close（fd）;
close（fw）;
return 0;
}