A copy console applicaton on ubuntu

#include<iostream>
#include<unistd.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
using namespace std;
int main(){
	int fd1,fd2;//file descibe
	char buf[1];//buffer
	int rd=0,wr=0;
	fd1=open("//home//hhj//Documents//hello.cpp",O_RDONLY);
	fd2=open("//home//hhj//Documents//a.txt",O_WRONLY);
	if(fd1==-1||fd2==-1){
		cout<<"open error"<<endl;
	}
	else{
		rd=read(fd1,buf,1);
		while(rd!=0){
			if(rd==-1){cout<<"read error"<<endl;break;}
			else{
				wr=write(fd2,buf,1);
				if(wr==-1){cout<<"write error"<<endl;break;}
				else{
					rd=read(fd1,buf,1);
				}
			}
		}

	}
	fd1=close(fd1);
	fd2=close(fd2);
	if(fd1==-1||fd2==-1)cout<<"close error"<<endl;
	return 0;
}

The code above is to copy the file hello.cpp to a.txt.It's only useful for linux OS.