hole.c

unix高级编程源代码.<<unix高级编程>>

#include	<sys/types.h>
#include	<sys/stat.h>
#include	<fcntl.h>
#include	"ourhdr.h"

char	buf1[] = "abcdefghij";
char	buf2[] = "ABCDEFGHIJ";

int
main(void)
{
	int		fd;

	if ( (fd = creat("file.hole", FILE_MODE)) < 0)
		err_sys("creat error");

	if (write(fd, buf1, 10) != 10)
		err_sys("buf1 write error");
	/* offset now = 10 */

	if (lseek(fd, 40, SEEK_SET) == -1)
		err_sys("lseek error");
	/* offset now = 40 */

	if (write(fd, buf2, 10) != 10)
		err_sys("buf2 write error");
	/* offset now = 50 */

	exit(0);
}