Windows Shell Items: Perl parsing library

Windows Shell Items (AKA "shellbags") is an undocumented set of structures used internally within Windows to identify paths in Windows Folder Hierarchy. It is widely used in Windows Shell (and most visible in File Explorer), both as in-memory and in-file structures. Some formats embed them, namely:

  • Windows Shell link files (.lnk) Windows registry
  • Windows registry "ShellBags" keys

The format is mostly undocumented, and is known to vary between various Windows versions.

KS implementation details

License: CC0-1.0

References

This page hosts a formal specification of Windows Shell Items using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Perl source code to parse Windows Shell Items

WindowsShellItems.pm

# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

use strict;
use warnings;
use IO::KaitaiStruct 0.007_000;

########################################################################
package WindowsShellItems;

our @ISA = 'IO::KaitaiStruct::Struct';

sub from_file {
    my ($class, $filename) = @_;
    my $fd;

    open($fd, '<', $filename) or return undef;
    binmode($fd);
    return new($class, IO::KaitaiStruct::Stream->new($fd));
}

sub new {
    my ($class, $_io, $_parent, $_root) = @_;
    my $self = IO::KaitaiStruct::Struct->new($_io);

    bless $self, $class;
    $self->{_parent} = $_parent;
    $self->{_root} = $_root || $self;;

    $self->_read();

    return $self;
}

sub _read {
    my ($self) = @_;

    $self->{items} = ();
    do {
        $_ = WindowsShellItems::ShellItem->new($self->{_io}, $self, $self->{_root});
        push @{$self->{items}}, $_;
    } until ($_->len_data() == 0);
}

sub items {
    my ($self) = @_;
    return $self->{items};
}

########################################################################
package WindowsShellItems::ShellItemData;

our @ISA = 'IO::KaitaiStruct::Struct';

sub from_file {
    my ($class, $filename) = @_;
    my $fd;

    open($fd, '<', $filename) or return undef;
    binmode($fd);
    return new($class, IO::KaitaiStruct::Stream->new($fd));
}

sub new {
    my ($class, $_io, $_parent, $_root) = @_;
    my $self = IO::KaitaiStruct::Struct->new($_io);

    bless $self, $class;
    $self->{_parent} = $_parent;
    $self->{_root} = $_root || $self;;

    $self->_read();

    return $self;
}

sub _read {
    my ($self) = @_;

    $self->{code} = $self->{_io}->read_u1();
    my $_on = $self->code();
    if ($_on == 31) {
        $self->{body1} = WindowsShellItems::RootFolderBody->new($self->{_io}, $self, $self->{_root});
    }
    my $_on = ($self->code() & 112);
    if ($_on == 32) {
        $self->{body2} = WindowsShellItems::VolumeBody->new($self->{_io}, $self, $self->{_root});
    }
    elsif ($_on == 48) {
        $self->{body2} = WindowsShellItems::FileEntryBody->new($self->{_io}, $self, $self->{_root});
    }
}

sub code {
    my ($self) = @_;
    return $self->{code};
}

sub body1 {
    my ($self) = @_;
    return $self->{body1};
}

sub body2 {
    my ($self) = @_;
    return $self->{body2};
}

########################################################################
package WindowsShellItems::ShellItem;

our @ISA = 'IO::KaitaiStruct::Struct';

sub from_file {
    my ($class, $filename) = @_;
    my $fd;

    open($fd, '<', $filename) or return undef;
    binmode($fd);
    return new($class, IO::KaitaiStruct::Stream->new($fd));
}

sub new {
    my ($class, $_io, $_parent, $_root) = @_;
    my $self = IO::KaitaiStruct::Struct->new($_io);

    bless $self, $class;
    $self->{_parent} = $_parent;
    $self->{_root} = $_root || $self;;

    $self->_read();

    return $self;
}

sub _read {
    my ($self) = @_;

    $self->{len_data} = $self->{_io}->read_u2le();
    if ($self->len_data() >= 2) {
        $self->{_raw_data} = $self->{_io}->read_bytes(($self->len_data() - 2));
        my $io__raw_data = IO::KaitaiStruct::Stream->new($self->{_raw_data});
        $self->{data} = WindowsShellItems::ShellItemData->new($io__raw_data, $self, $self->{_root});
    }
}

sub len_data {
    my ($self) = @_;
    return $self->{len_data};
}

sub data {
    my ($self) = @_;
    return $self->{data};
}

sub _raw_data {
    my ($self) = @_;
    return $self->{_raw_data};
}

########################################################################
package WindowsShellItems::RootFolderBody;

our @ISA = 'IO::KaitaiStruct::Struct';

sub from_file {
    my ($class, $filename) = @_;
    my $fd;

    open($fd, '<', $filename) or return undef;
    binmode($fd);
    return new($class, IO::KaitaiStruct::Stream->new($fd));
}

sub new {
    my ($class, $_io, $_parent, $_root) = @_;
    my $self = IO::KaitaiStruct::Struct->new($_io);

    bless $self, $class;
    $self->{_parent} = $_parent;
    $self->{_root} = $_root || $self;;

    $self->_read();

    return $self;
}

sub _read {
    my ($self) = @_;

    $self->{sort_index} = $self->{_io}->read_u1();
    $self->{shell_folder_id} = $self->{_io}->read_bytes(16);
}

sub sort_index {
    my ($self) = @_;
    return $self->{sort_index};
}

sub shell_folder_id {
    my ($self) = @_;
    return $self->{shell_folder_id};
}

########################################################################
package WindowsShellItems::VolumeBody;

our @ISA = 'IO::KaitaiStruct::Struct';

sub from_file {
    my ($class, $filename) = @_;
    my $fd;

    open($fd, '<', $filename) or return undef;
    binmode($fd);
    return new($class, IO::KaitaiStruct::Stream->new($fd));
}

sub new {
    my ($class, $_io, $_parent, $_root) = @_;
    my $self = IO::KaitaiStruct::Struct->new($_io);

    bless $self, $class;
    $self->{_parent} = $_parent;
    $self->{_root} = $_root || $self;;

    $self->_read();

    return $self;
}

sub _read {
    my ($self) = @_;

    $self->{flags} = $self->{_io}->read_u1();
}

sub flags {
    my ($self) = @_;
    return $self->{flags};
}

########################################################################
package WindowsShellItems::FileEntryBody;

our @ISA = 'IO::KaitaiStruct::Struct';

sub from_file {
    my ($class, $filename) = @_;
    my $fd;

    open($fd, '<', $filename) or return undef;
    binmode($fd);
    return new($class, IO::KaitaiStruct::Stream->new($fd));
}

sub new {
    my ($class, $_io, $_parent, $_root) = @_;
    my $self = IO::KaitaiStruct::Struct->new($_io);

    bless $self, $class;
    $self->{_parent} = $_parent;
    $self->{_root} = $_root || $self;;

    $self->_read();

    return $self;
}

sub _read {
    my ($self) = @_;

    $self->{_unnamed0} = $self->{_io}->read_u1();
    $self->{file_size} = $self->{_io}->read_u4le();
    $self->{last_mod_time} = $self->{_io}->read_u4le();
    $self->{file_attrs} = $self->{_io}->read_u2le();
}

sub is_dir {
    my ($self) = @_;
    return $self->{is_dir} if ($self->{is_dir});
    $self->{is_dir} = ($self->_parent()->code() & 1) != 0;
    return $self->{is_dir};
}

sub is_file {
    my ($self) = @_;
    return $self->{is_file} if ($self->{is_file});
    $self->{is_file} = ($self->_parent()->code() & 2) != 0;
    return $self->{is_file};
}

sub _unnamed0 {
    my ($self) = @_;
    return $self->{_unnamed0};
}

sub file_size {
    my ($self) = @_;
    return $self->{file_size};
}

sub last_mod_time {
    my ($self) = @_;
    return $self->{last_mod_time};
}

sub file_attrs {
    my ($self) = @_;
    return $self->{file_attrs};
}

1;