Net::VNC(3) A simple VNC client

SYNOPSIS


use Net::VNC;
my $vnc = Net::VNC->new({hostname => $hostname, password => $password});
$vnc->depth(24);
$vnc->login;
print $vnc->name . ": " . $vnc->width . ' x ' . $vnc->height . "\n";
my $image = $vnc->capture;
$image->save("out.png");

DESCRIPTION

Virtual Network Computing (VNC) is a desktop sharing system which uses the RFB (Remote FrameBuffer) protocol to remotely control another computer. This module acts as a VNC client and communicates to a VNC server using the RFB protocol, allowing you to capture the screen of the remote computer.

This module dies upon connection errors (with a timeout of 15 seconds) and protocol errors.

This implementation is based largely on the RFB Protocol Specification, <http://www.realvnc.com/docs/rfbproto.pdf>. That document has an error in the DES encryption description, which is clarified via <http://www.vidarholen.net/contents/junk/vnc.html>.

METHODS

new

The constructor. Given a hostname and a password returns a Net::VNC object: 

  my $vnc = Net::VNC->new({hostname => $hostname, password => $password});

Optionally, you can also specify a port, which defaults to 5900. For ARD (Apple Remote Desktop) authentication you must also specify a username. You must also install Crypt::GCrypt::MPI and Crypt::Random.

login

Logs into the remote computer: 

  $vnc->login;

name

Returns the name of the remote computer: 

  print $vnc->name . ": " . $vnc->width . ' x ' . $vnc->height . "\n";

width

Returns the width of the remote screen: 

  print $vnc->name . ": " . $vnc->width . ' x ' . $vnc->height . "\n";

height

Returns the height of the remote screen: 

  print $vnc->name . ": " . $vnc->width . ' x ' . $vnc->height . "\n";

capture

Captures the screen of the remote computer, returning an Image::Imlib2 object: 

  my $image = $vnc->capture;
  $image->save("out.png");

You may call capture() multiple times. Each time, the $image buffer is overwritten with the updated screen. So, to create a series of ten screen shots: 

  for my $n (1..10) {
    my $filename = sprintf 'snapshot%02d.png', $n++;
    $vnc->capture()->save($filename);
    print "Wrote $filename\n";
  }

depth

Specify the bit depth for the screen. The supported choices are 24, 16 or 8. If unspecified, the server's default value is used. This property should be set before the call to login().

save_bandwidth

Accepts a boolean, defaults to false. Specifies whether to use more CPU-intensive algorithms to compress the VNC datastream. LAN or localhost connections may prefer to leave this false. This property should be set before the call to login().

list_encodings

Returns a list of encoding number/encoding name pairs. This can be used as a class method like so: 

   my %encodings = Net::VNC->list_encodings();

send_key_event_down

Send a key down event. The keys are the same as the corresponding ASCII value. Other common keys: 

  BackSpace 0xff08
  Tab 0xff09
  Return or Enter 0xff0d
  Escape 0xff1b
  Insert 0xff63
  Delete 0xffff
  Home 0xff50
  End 0xff57
  Page Up 0xff55
  Page Down 0xff56
  Left 0xff51
  Up 0xff52
  Right 0xff53
  Down 0xff54
  F1 0xffbe
  F2 0xffbf
  F3 0xffc0
  F4 0xffc1
  ... ...
  F12 0xffc9
  Shift (left) 0xffe1
  Shift (right) 0xffe2
  Control (left) 0xffe3
  Control (right) 0xffe4
  Meta (left) 0xffe7
  Meta (right) 0xffe8
  Alt (left) 0xffe9
  Alt (right) 0xffea
  $vnc->send_key_event_down('A');

send_key_event_up

Send a key up event: 

  $vnc->send_key_event_up('A');

send_key_event

Send a key down event followed by a key up event: 

  $vnc->send_key_event('A');

send_key_event_string

Send key events for every character in a string: 

  $vnc->send_key_event_string('Hello');

send_pointer_event( $button_mask, $x, $y )

Send pointer event (usually a mouse). This is used to move the pointer or make clicks or drags.

It is easier to call the "mouse_move" or <mouse_click> methods instead.

mouse_move_to($x, $y)

Send the pointer to the given position. The cursor instantly jumps there instead of smoothly moving to there.

mouse_click

Click on current pointer position.

mouse_right_click

Right-click on current pointer position.

BUGS AND LIMITATIONS

Bit depth

We do not yet support 8-bit true-colour mode, which is commonly supported by servers but is rarely employed by clients.

Byte order

We have currently tested this package against servers with the same byte order as the client. This might break with a little-endian server/big-endian client or vice versa. We're working on tests for those latter cases. Testing and patching help would be appreciated.

Efficiency

We've implemented a subset of the data compression algorithms supported by most VNC servers. We hope to add more of the high-compression transfer encodings in the future.

AUTHORS

Leon Brocard [email protected]

Chris Dolan [email protected]

Apple Remote Desktop authentication based on LibVNCServer

Maurice Castro [email protected]

Many thanks for Foxtons Ltd for giving Leon the opportunity to write the original version of this module.

Copyright (C) 2006, Leon Brocard

This module is free software; you can redistribute it or modify it under the same terms as Perl itself.

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