SCR/SCR3.1/TP2/eraser.c

#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>
#define BLOCK_SIZE 1

int main(int argc, char **argv){
	int fd, fd1;
        ssize_t	read_bytes, wrote_bytes;
	char buf[BLOCK_SIZE];
	char *name;
	if (argc != 2){
		printf("Usage : %s <path_to_the_file_to_erase>", argv[0]);
		exit(EXIT_FAILURE);
	}
	struct stat sb;
	if (stat(argv[1], &sb) == -1){
		perror("stat");
		exit(EXIT_FAILURE);
	}
	if (sb.st_nlink > (nlink_t) 1) {
		unlink(argv[1]);
		exit(EXIT_FAILURE);
	}
	else {
		fd = open(argv[1], O_SYNC|O_RDONLY);
		if (fd == -1){
			perror("fd");
			exit(EXIT_SUCCESS);
		}
		while (read_bytes = read(fd,buf,BLOCK_SIZE) > 0) {
			wrote_bytes = write(fd,"0xff",BLOCK_SIZE);
		}

		fd1 = open("/dev/urandom", O_RDONLY);
		while (read(fd, buf, BLOCK_SIZE) > 0) {
			read_bytes = read(fd1, buf, BLOCK_SIZE);
			wrote_bytes = write(fd, buf, BLOCK_SIZE);
		}
		srand(time(NULL));
		name = "file" + (char) rand() + ".crypt";
		rename(argv[1], name);
		unlink(name);
	}
	close(fd);
	close(fd1);
	return EXIT_SUCCESS;
}