#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>

#define SZBUF 256

int main(int argc, char const *argv[]){
	char buf[SZBUF];
	int fs,fd,n,m;
	if (argc<3){
		fprintf(stderr,"Usage : %s <SRC_FILE><bSR_FILE> \r",argv[0]);
		exit (1);
	} fs=open (argv[1], O_RDONLY);
	if (fs==-1){
		perror("Opening source file fails");
		exit(2);
	} fd=open (argv[2], O_WRONLY|O_TRUNC|O_CREAT,0b00);
	if (fd==-1){
		perror("Opening destination file fails");
		exit(3);
	} while (n=read(fs,buf,SZBUF)){
		m=write(fd,buf,n);
		if (m==-1){
			perror("Writing in file fails");
			exit(4);
		}
	} close(fs);
	close(fd);
	exit(0);
}