#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include <sys/types.h>	/* open */
#include <sys/stat.h>	/* open */
#include <fcntl.h>	/* O_CREAT, O_RDONLY */
#include <unistd.h>	/* close, lseek, read, write */

#include "utils.h"

/* Print the last 100 bytes from a file */

int main (void)
{
	int fd, rc;
	char *buf;
	ssize_t bytes_read;

	/* alocate space for the read buffer */
	buf = malloc(101);
	DIE(buf == NULL, "malloc");

	/* open file */
	fd = open("file.txt", O_RDONLY);
	DIE(fd < 0, "open");

	/* set file pointer at 100 characters
	 _before_ the end of the file */
	rc = lseek(fd, -100, SEEK_END);
	DIE(rc < 0, "lseek");

	/* read the last 100 characthers */
	bytes_read = read(fd, buf, 100);
	DIE(bytes_read < 0, "read");

	/* set '\0' at end of buffer for printing purposes*/
	buf[bytes_read] = '\0';

	printf("the last %ld bytes: \n%s\n", bytes_read, buf);

	/* close file */
	rc = close(fd);
	DIE(rc < 0, "close");

	/* cleanup */
	free(buf);

	return 0;
}