Program that scrapes the big wav file from the damaged filesystem (FAT borked); throwaway code

collect_wav_file.c

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

int iszero (char *buf, int size) {
	int i;
	int z = 0;
	for (i = 0; i < size; i ++) {
		if (buf [i] == 0) z ++;
	}
	return z + 100 >= size;
}

int main () {
	int fd = open ("/Volumes/Ext/8gb.dump", 0);
	int i;
	long long p = 101122048;
	int lz = 0;
	int z = 0;
	int ofd = creat ("o1.wav", 644);
	lseek (fd, p, 0);
	for (i = 0; i <= 29100; i ++) {
		char buf [32768];
		int r = read (fd, buf, sizeof (buf));
		if (r != sizeof (buf)) {
			printf ("Hey!\n");
			return 1;
		}
		if (iszero (buf, sizeof (buf))) {
			printf ("Zero %d (%d)\n", i, i - lz);
			lz = i;
			z ++;
			if (z > 20) {
				printf ("Enough\n");
				break;
			}
			continue;
		}
		z = 0;
		r = write (ofd, buf, sizeof (buf));
		if (r != sizeof (buf)) {
			printf ("Yeh!\n");
			return 1;
		}
	}
	close (fd);
	close (ofd);
}

riff.c

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

static void dofile (char *fn) {
	long long pos = 0;
	int fd = open (fn, 0);
	if (fd == -1) {
		printf ("Can't open %s\n", fn);
		return;
	}
	while (1) {
		char buf [65536];
		int i;
		int r = read (fd, buf, sizeof (buf));
		if (r != sizeof (buf)) {
			printf ("Read only %d bytes at %llx\n", r, pos);
			close (fd);
			return;
		}
		for (i = 0; i < sizeof (buf); i += 512) {
			if (buf [i] == 'R' &&
			    buf [i + 1] == 'I' &&
			    buf [i + 2] == 'F' &&
			    buf [i + 3] == 'F')
			{
				int k;
				for (k = 0; k < 16; k ++) {
					char c = buf [i + k];
					printf ("%c",
						c > ' ' && c <= '~' ? c : '.');
				}
				printf (" at %llx (%lld)\n",
					pos + i,
					pos + i);
			}
		}
		pos += sizeof (buf);
	}
	close (fd);
}

int main (int argc, char **argv) {
	int i;
	for (i = 1; i < argc; i ++) {
		dofile (argv [i]);
	}
	return 0;
}

riff finds the start of the wav files, the other thingie scrapes them from disk, assuming linear storage with a few blocks omitted (i have no idea why it did that).