// C program to illustrate close system Call
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>

int main()
{
	int fd1 = open("data.txt", O_WRONLY | O_CREAT | O_TRUNC, 0644) ;
	int sz ;
	if (fd1 < 0)
	{
		perror("c1");
		return(1);
	}
	printf("opened the fd = % d\n", fd1);
    sz = write(fd1, "hello class\n", strlen("hello class\n"));

	// Using close system Call
	if (close(fd1) < 0)
	{
		perror("c1") ;
		return(1) ;
	}
	printf("closed the fd.\n");
	return( 0 ) ;
}