#! /usr/bin/perl

use strict;
use warnings;

my $count = 0;
my $offset = 0;
my ($buf, $blen, $len, $n);

while(read (STDIN, $buf, 4) == 4) {
  if (unpack('N', $buf) == 0x42faedfe) {
    printf "found an image: %x\n", $offset;
    if (read (STDIN, $blen, 4) == 4) {
      $offset += 4;
      $len = unpack('V', $blen) + 16;
      printf "length %d\n", $len;
      {
        use integer;
        $len = (($len+3)/4)*4;
      }
      printf "length %d\n", $len;
      open OUT, ">$count.image" or die "$!";
      print OUT $buf, $blen;
DUMP:
      while ($len > 0 && ($n = read (STDIN, $buf, ($len > 1024?1024:$len))) > 0) {
        $len -= $n;
	$offset += $n;
	print OUT $buf;
      }
      close OUT;
      if ($len) {
        die "short image in input: $len";
      }
    } else {
      die "can't read len from possible image";
    }
    $count++;
  }
  elsif (unpack('V', $buf) == 0x73717368) {
    printf "found an le squashfs: %x\n", $offset;
    my $dummy;
    if (read(STDIN, $dummy, 4) == 4 && read(STDIN, $blen, 4) == 4) {
      $offset += 8;
      $len = unpack('V', $blen);
      printf "length %d\n", $len;
      {
	use integer;
	$len = (($len+3)/4)*4;
      }
      printf "length %d\n", $len;
      open OUT, ">$count.image" or die "$!";
      print OUT $buf, $dummy, $blen;
      goto DUMP;
    }
  }
  $offset += 4;
}