/*
 *	A simple minded, 5 minute, program to trash all free blocks on a
 *	disk by just writing a file full of garbage until the disk is full.
 *
 *	This insures that any proprietary data left on the disk after
 *	deleting files is clobbered.   Otherwise, disksalv might find
 *	some interesting tidbits...
 *
 *	To use, just run and wait for the requestor to come up when
 *	the disk is full.  Cancel the requestor and the file "junkfile"
 *	will be left, and the disk will be full.  Delete the file
 *	to free up the scribbled blocks.
 *
 */

#include <stdio.h>

static char buf[512];

#define FILENAME "junkfile"
#define MSG "This block has been subjected to bit rot (better luck next time!)"

int main ()
{
	register FILE *fp;
	register int count = 0;

	if ((fp = fopen (FILENAME, "r")) != NULL) {
		(void) fprintf (stderr, "%s: file exists already!\n", FILENAME);
	} else {
		(void) fclose (fp);
		if ((fp = fopen (FILENAME, "w")) == NULL) {
			(void) fprintf (stderr, "%s: can't open for write!\n",
				FILENAME);
		} else {
			(void) strcpy (buf, MSG);
			while (fwrite (buf, sizeof (buf), 1, fp) == 1) {
				count++;
				if ((count % 100) == 0) {
					(void) printf ("Reached block %d ...\r",
						 count);
					(void) fflush (stdout);
				}
			}
			(void) printf ("Total of %d blocks written\n", count);
			(void) fflush (stdout);
			(void) fclose (fp);
		}			
	}
	return (0);
}