use strict;
use warnings;

(my $binStr = <<BIN) =~ s/\n//g;
\x01\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00
The end of the world is neigh   
\x03\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00
unless you use pack and unpack  
BIN

open my $fIn, '<', \$binStr;
binmode $fIn;

print "Using unpack\n";

while (read($fIn, (my $rec), 48)) {
    my ($fileLocL, undef, $fileSizeL, undef, $fileName) =
        unpack('VVVVa32', $rec);

    printf "Loc: %d, Size: %d, Name: '%s'\n", $fileLocL, $fileSizeL, $fileName;
}

seek $fIn, 0, 0;

print "Using bogus substitution code\n";

while (!eof $fIn) {
    my ($fileLoc, $fileSize, $fileName);

    read($fIn, $fileLoc,  0x08);
    read($fIn, $fileSize, 0x08);
    read($fIn, $fileName, 0x20);

    $fileLoc  =~ s/(.)/sprintf("%02x",ord($1))/eg;
    $fileSize =~ s/(.)/sprintf("%02x",ord($1))/eg;
    $fileName =~ s/\0+$//;

    printf "Loc: %d, Size: %d, Name: '%s'\n", $fileLoc, $fileSize, $fileName;
}

##</code><code>##

Using unpack
Loc: 1, Size: 2, Name: 'The end of the world is neigh   '
Loc: 3, Size: 4, Name: 'unless you use pack and unpack  '
Using bogus substitution code
Loc: -1, Size: -1, Name: 'The end of the world is neigh   '
Loc: -1, Size: -1, Name: 'unless you use pack and unpack  '