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✏️ Editing: zipinfo.pl

#!/usr/bin/perl -w
# Print out information about a ZIP file.
# Note that this buffers the entire file into memory!
# usage:
# perl examples/zipinfo.pl zipfile.zip

use strict;

use Data::Dumper ();
use FileHandle;
use Archive::Zip qw(:ERROR_CODES :CONSTANTS :PKZIP_CONSTANTS);
use Archive::Zip::BufferedFileHandle;

$| = 1;

### Workaround for a bug in version of Data::Dumper bundled
### with some versions of Perl, which causes warnings when
### calling ->Seen below.
if (defined &Data::Dumper::init_refaddr_format) {
    Data::Dumper::init_refaddr_format();
}

# use constant END_OF_CENTRAL_DIRECTORY_SIGNATURE_STRING;
use constant CENTRAL_DIRECTORY_FILE_HEADER_SIGNATURE_STRING =>
  pack(SIGNATURE_FORMAT, CENTRAL_DIRECTORY_FILE_HEADER_SIGNATURE);
use constant LOCAL_FILE_HEADER_SIGNATURE_STRING =>
  pack(SIGNATURE_FORMAT, LOCAL_FILE_HEADER_SIGNATURE);

$Data::Dumper::Useqq  = 1;    # enable double-quotes for string values
$Data::Dumper::Indent = 1;

my $zip         = Archive::Zip->new();
my $zipFileName = shift(@ARGV);

my $fh = Archive::Zip::BufferedFileHandle->new();
$fh->readFromFile($zipFileName) or exit($!);

my $status = $zip->_findEndOfCentralDirectory($fh);
die("can't find EOCD\n") if $status != AZ_OK;

my $eocdPosition = $fh->tell();

$status = $zip->_readEndOfCentralDirectory($fh);
die("can't read EOCD\n") if $status != AZ_OK;

my $zipDumper = Data::Dumper->new([$zip], ['ZIP']);
$zipDumper->Seen({ref($fh), $fh});
print $zipDumper->Dump(), "\n";

my $expectedEOCDPosition =
  $zip->centralDirectoryOffsetWRTStartingDiskNumber() +
  $zip->centralDirectorySize();

my $eocdOffset = $zip->{eocdOffset} = $eocdPosition - $expectedEOCDPosition;

if ($eocdOffset) {
    printf "Expected EOCD at %d (0x%x) but found it at %d (0x%x)\n",
      ($expectedEOCDPosition) x 2, ($eocdPosition) x 2;
} else {
    printf("Found EOCD at %d (0x%x)\n\n", ($eocdPosition) x 2);
}

my $contents = $fh->contents();
my $offset   = $eocdPosition + $eocdOffset - 1;
my $cdPos;
my @members;
my $numberOfMembers = $zip->numberOfCentralDirectoriesOnThisDisk();
foreach my $n (0 .. $numberOfMembers - 1) {
    my $index = $numberOfMembers - $n;
    $cdPos = rindex($contents,
        CENTRAL_DIRECTORY_FILE_HEADER_SIGNATURE_STRING, $offset);
    if ($cdPos < 0) {
        print "No central directory found for member #$index\n";
        last;
    } else {
        print "Found central directory for member #$index at $cdPos\n";
        $fh->seek($cdPos + SIGNATURE_LENGTH, 0);    # SEEK_SET
        my $newMember =
          Archive::Zip::Member->_newFromZipFile($fh, "($zipFileName)");
        $status = $newMember->_readCentralDirectoryFileHeader();
        if ($status != AZ_OK and $status != AZ_STREAM_END) {
            printf "read CD header status=%d\n", $status;
            last;
        }
        unshift(@members, $newMember);

my $memberDumper =
          Data::Dumper->new([$newMember], ['CDMEMBER' . $index]);
        $memberDumper->Seen({ref($fh), $fh});
        print $memberDumper->Dump(), "\n";
    }
    $offset = $cdPos - 1;
}

if (    $cdPos >= 0
    and $cdPos != $zip->centralDirectoryOffsetWRTStartingDiskNumber()) {
    printf
      "Expected to find central directory at %d (0x%x), but found it at %d (0x%x)\n",
      ($zip->centralDirectoryOffsetWRTStartingDiskNumber()) x 2,
      ($cdPos) x 2;
}

print "\n";

# Now read the local headers

foreach my $n (0 .. $#members) {
    my $member = $members[$n];
    $fh->seek(
        $member->localHeaderRelativeOffset() + $eocdOffset + SIGNATURE_LENGTH,
        0);
    $status = $member->_readLocalFileHeader();
    if ($status != AZ_OK and $status != AZ_STREAM_END) {
        printf "member %d read header status=%d\n", $n + 1, $status;
        last;
    }

my $memberDumper = Data::Dumper->new([$member], ['LHMEMBER' . ($n + 1)]);
    $memberDumper->Seen({ref($fh), $fh});
    print $memberDumper->Dump(), "\n";

my $endOfMember =
      $member->localHeaderRelativeOffset() +
      $member->_localHeaderSize() +
      $member->compressedSize();

if (
        $endOfMember > $cdPos
        or (    $n < $#members
            and $endOfMember > $members[$n + 1]->localHeaderRelativeOffset())
      ) {
        print "Error: ";
    }
    printf("End of member: %d, CD at %d", $endOfMember, $cdPos);
    if ($n < $#members) {
        printf(", next member starts at %d",
            $members[$n + 1]->localHeaderRelativeOffset());
    }
    print("\n\n");
}

# vim: ts=4 sw=4

MR SKB