barrier/README

synergy
-------
synergy: [noun] a mutually advantageous conjunction of distinct elements

synergy lets you easily share a single mouse and keyboard between
multiple computers, each with its own display, using software only.
redirecting the mouse and keyboard is as simple as moving the mouse
off the edge of your screen.  synergy merges the clipboards of all
the systems into one, allowing cut-and-paste between systems.  it
also synchronizes screensavers so they all start and stop together
and, if screen locking is enabled, only one screen requires a
password to unlock them all.


system requirements
-------------------
all systems:
  keyboard
  mouse
  TCP/IP networking

Microsoft Windows 95, Windows 98, Windows Me (the Windows 95 family):
  ??? MB RAM

Microsoft Windows NT, Windows 2000, Windows XP (the Windows NT family):
  ??? MB RAM

Linux, Unix:
  ??? MB RAM
  X Windows, revision 4 or up with the XTEST extension
    use `xdpyinfo | grep XTEST' to check


manifest
--------
  linux               windows
  -----               -------
  README              README              this file
  synergy             synergy.exe         the synergy client
  synergyd            synergyd.exe        the synergy server
                      synrgyhk.dll        the synergy hook dll
  synergy.conf        synergy.conf        sample configuration file


running synergy
---------------
synergy is simple to configure.  the server uses a configuration file
and command line options while the client uses only command line
options.  it's recommended that both the client and server be run in
the foreground until the configuration is verified to work.

step 1:  create a configuration file
  edit the sample configuration file.  there are two sections you
  must fill in and a third optional section.  you should delete
  the existing lines inside the sections.

  in the "screens" section, add a line for each computer you'll
  be using (server and clients).  put the hostname of the computer
  followed by a colon (with no space in between).  the computers
  can be listed in any order.

  in the "links" section you define how screens are connected.
  each screen is listed as in the "screens" section except
  following each screen is a list of links to other screens in
  the form "<direction> = <screen>" where <direction> is "left",
  "right", "up", or "down" and <screen> is a screen listed in
  the "screens" section.

  as an example, if we have "left=foo" under the "bar" screen
  then screen "foo" is on the left of screen "bar".  the user
  will be able to move the mouse off the left edge of "foo" and
  will appear on the opposite (right) edge of "bar".  note that
  it's entirely possible to have one-way (asymmetric) links and
  screens with only links into them.  the latter should be
  avoided since there's no way to move the mouse off those
  screens.

  in the "aliases" section you can list other names for each
  screen.  this is especially useful for dealing with fully
  qualified domain names versus simple hostnames.

step 2:  start the server
  the server is the system with the mouse and keyboard to be
  shared.  each platform has its own tradeoffs when running as
  the server.  see the release notes below for more information.

  run the synergy server on the server system using the following
  command line:

    synergyd -f --config <config-pathname>

  replacing <config-pathname> with the path to the configuration
  file.  you can use `synergyd --help' for a list of command line
  options.

step 3:  start the clients
  on each client system start the synergy client using the
  following command line:

    synergy -f --debug INFO --no-camp <server-hostname>

  replacing <server-hostname> with the hostname or address of the
  server system.

  the client should quickly report `connected to server'.  if it
  does not but doesn't print an error and exit immeditately then
  it's trying to connect to the server but cannot.  it will time
  out in 30 seconds and exit (use ctrl+c to exit earlier).  you
  should check that the server is running and try again.

  otherwise, if the client doesn't connect it should print an
  error describing the problem.  here are typical problems and
  possible solutions:

    failed to open screen:
      check permission to open the X display;
      check that the DISPLAY environment variable is set.
    already connected:
      check that synergy isn't already running.
    refused client:
      add client to the server's configuration file.
    connection failed:
      check server-hostname;
      the server cannot open the desired port, stop the
      program using that port (24800) and restart the
      server.

step 4:  verify the configuration
  once the clients are connected, use the mouse to check that
  the screens are properly linked.  moving the mouse off the
  edge of a screen with a link should cause it to appear on
  the opposite edge of the linked-to screen.


using synergy
-------------
using synergy is very easy.  once clients have connected to the
server all you do to redirect keyboard and mouse input to a screen
(i.e. switch screens) is move the mouse cursor off the edge of the
screen you're on.  which edges go to which screens depends on the
configuration.

clients can be connected and disconnected at any time.  until a
client is connected, switching to it works as if you switched to
it then moved all the way across it in the same direction and
switched to the next screen.  this repeats until you reach a
connected screen.  if there is no connected screen in that
direction then the mouse will not leave the starting screen.

disconnecting a client while the mouse is on it causes the mouse
to instantly jump to the center of the server screen.

the clipboard is automatically transferred between screens.  if
you copy on one screen you just switch to another screen and paste.
note that X Windows has two major clipboards:  the primary
selection and the clipboard.  synergy supports both.  however,
Microsoft Windows only supports the clipboard.  the Windows
clipboard is transferred to both the X primary selection and the
clipboard.  whichever X clipboard was changed last becomes the
Windows clipboard.  end-of-line sequences (LF on linux and unix,
CRLF on Windows) are automatically converted as necessary.  the
clipboards are transferred using Unicode;  if your platforms and
applications understand Unicode then you should be able to cut
and paste any Unicode character.

synergy synchronizes screensavers.  the screensavers on client
screens are disabled when they connect to the server.  when the
primary screen's screensaver starts, the screensaver on each
secondary screen starts too.  all the secondary screensavers are
stopped when the primary screensaver stops.  moving the mouse or
pressing a key will stop the primary screensaver, regardless of
which screen the mouse was on when the screensavers started.  if
the primary screensaver requires a password to unlock then the
user is prevented from switching to the secondary screens until
the primary screen is unlocked.


installing as a daemon/service
------------------------------
synergy can run in the foreground or as a daemon/service.  it's
recommended that you run it in the foreground until you've sorted
out your configuration.

on the Windows NT family you cannot run a service directly.
instead you install the service then run or stop it via the
Services control panel.  on the Windows 95 family, you can use
the `--daemon' command line option to start synergy as a service
or you can install the service and restart your computer.

in the text below, except where noted, synergy refers to the
client and/or the server.

windows:
  to install synergy just run one of the following:

    synergy --install [other command line options]
    synergyd --install [other command line options]

  the client/server is installed as a service and the command
  line is saved and used when starting the service.  the system
  will expect to find the program wherever it was when you used
  the --install option so make sure it's not on a network share
  from another system because the network share will not be
  available at boot time.  synergyd will also try to load
  synrgyhk.dll so that should be in the same directory as
  synergyd.exe.

  note that when installing the client you must provide the
  server hostname argument.  to change the arguments you must
  first uninstall then reinstall.

  you must also install the configuration file along with the
  server.  it's recommended that you put it in the windows
  directory (e.g. C:\WINNT) and call it "synergy.sgc".  the
  server will automatically find this file.  however, you can
  also use the --config command line option and specify an
  *absolute* path to the file.  remember that this file must be
  accessible when the system starts up, before network shares
  are mapped.

  to uninstall use:

    synergy --uninstall
    synergyd --uninstall

linux, unix:
  before starting synergy as a daemon you should understand that
  synergy requires an X server that it can connect to.  synergy
  can start before the X server does and will repeatly attempt to
  connect to the X server until it succeeds.  however, if the
  server requires authorization then it's unlikely that synergy
  will ever succeed.  so, in general, synergy should be (re)started
  by the X display manager.

  some display managers (xdm and kdm, but not gdm) grab the
  keyboard and do not release it until the user logs in, also
  for security reasons.  this prevents a synergy server from
  sharing the mouse and keyboard until the user logs in but
  it doesn't prevent a synergy client from synthesizing mouse
  and keyboard input.

  you should modify xdm's Xsetup script to start the synergy
  client or server.  for example, somewhere near the bottom of
  Xsetup (but someplace before anywhere the script calls exit)
  you might add:
    /usr/bin/killall synergy
    /usr/sbin/synergy 192.168.1.101
  this assumes synergy is installed in /usr/sbin.  these lines
  make sure any already running synergy is terminated and starts
  a fresh copy.  it's important to kill old copies so that you
  don't end up with multiple synergy instances fighting each
  other or, at the very least, using up system resources.

  to start the synergy server you might use:
    /usr/bin/killall synergyd
    /usr/sbin/synergyd --config /root/synergy.conf
  assuming synergyd is installed in /usr/sbin.  if you've put
  the configuration data in /etc/synergy.conf then you don't
  need the --config option.

  another option is to put the synergy startup in .Xsession in
  your home directory.  that allows users without root access to
  start synergy when they login.  in this case synergy will not
  be running while on the login screen.


common command line options
---------------------------
  -d, --debug <level>   use debugging level <level>
      --daemon          run as a daemon (linux,unix) or background (windows)
  -f, --no-daemon       run in the foreground
  -n, --name <name>     use <name> instead of the hostname
      --restart         automatically restart on failures
  -1, --no-restart      do not restart on failure
  -h, --help            print help and exit
      --version         print version information and exit
      --install         install as a service (windows)
      --uninstall       uninstall service (windows)

debug levels are from highest to lowest:  FATAL, ERROR, WARNING, NOTE,
INFO, DEBUG, DEBUG1, and DEBUG2.  only messages at or above the given
level are logged.  messages are logged to a terminal window when
running in the foreground.  unix logs messages to syslog when running
as a daemon.  the Windows NT family logs messages to the event log
when running as a service.  the Windows 95 family shows FATAL log
messages in a message box and others in a terminal window when running
as a service.

the `--name' option lets the client or server use a name other than
its hostname for its screen.  this name is used when checking the
configuration.

neither the client nor server will automatically restart if an error
occurs that is sure to happen every time.  for example, the server
will exit immediately if it can't find itself in the screen
configuration.  on X11 both the client and server will also terminate
if the connection to the X server is lost.  since xdm will normally
restart the server and then synergy this is the correct behavior.


server command line options
---------------------------
  -a, --address <address>  listen for connections on the given address
  -c, --config <pathname>  read configuration from <pathname>

<address> has one of the following forms:
  <hostname>
  :<port>
  <hostname>:<port>
<hostname> is a hostname or address of a network interface on the
server system.  <port> is a port number from 1 to 65535.  <hostname>
defaults to the system's hostname and <port> defaults to 24800.


client command line options
---------------------------
  --camp                   retry connection to server until successful
  --no-camp                try connection to server only once
  <address>                address of server

see the "server command line options" for a description of <address>
but note that there is no default <hostname> though there is a
default <port>.


release notes
-------------
synergy does not yet fully capture all possible input or have full
control over the mouse and keyboard on all platforms.  each platform
has its own limitations and these limitations may influence your
choice for the server.

the following lists enumerate the limitations of each platform.  a
key (combination) that cannot be captured is not detected by synergy.
a key (combination) that cannot be blocked will be passed through to
the server system even when the mouse is on a client system.  if a
key cannot be captured then it also cannot be blocked.

windows 95 family, windows NT prior to service pack 3:
  * cannot capture:
    * ctrl+alt+del
    * ctrl+esc
    * alt+[shift+]tab
    * alt+[shift+]esc
    * windows+E
    * windows+[ctrl+]F
    * windows+[shift+]M
    * windows+R
    * windows+F1
    * windows+tab
    * windows+break
    * accessibility shortcuts (e.g. press shift 5 times for sticky keys)
      * the individual keys are captured but the dialogs still appear
  * cannot synthesize:
    * accessibility shortcuts

windows NT family (except NT prior to SP3):
  * cannot block:
    * ctrl+alt+del
    * accessibility shortcuts (e.g. press shift 5 times for sticky keys)
      * the individual keys are captured but the dialogs still appear
  * cannot synthesize:
    * accessibility shortcuts

linux, unix:
  * cannot capture:
    * ctrl+alt+del
    * ctrl+alt+backspace     (only if used by the X server)
    * ctrl+alt+keypad_plus   (only if used by the X server)
    * ctrl+alt+keypad_minus  (only if used by the X server)
  * keyboard/mouse grabs prevent switching screens for their duration
    * some display managers grab the keyboard until login

currently, the windows NT family (except NT prior to SP3) makes the
best server.


known bugs
----------
all:
  * non-ASCII keyboard characters are not supported

windows:
  * screen flashes when entering the screen
  * synergy may interfere with desktop switcher programs.  however,
    synergy understands and handles multiple desktops.
  * there should be a control panel
  * there should be a taskbar icon

windows 95 family:
  * typing into a console window can be slow

windows NT family:
  * the event viewer reports a message lookup error for synergy logs.
    however, the full synergy message is in the extra data portion of
    the event dialog.
  * does not gracefully handle NoInteractiveServices being enabled

linux:
  * some keyboards have toggle keys that toggle on on key press and
    toggle off on the key release after the next key press.  synergy
    doesn't handle these properly.
  * shift-lock (as opposed to caps-lock) is not supported
  * large (~256k) motif clipboard items are not copied properly


tips and tricks
---------------
* a screen can be its own neighbor.  that allows a screen to "wrap".
  for example, if a configuration linked the left and right sides of
  a screen to itself then moving off the left of the screen would put
  the mouse at the right of the screen and vice versa.

* you cannot switch screens when a key or mouse button is pressed.

* you cannot switch screens when the scroll lock it toggled on.  use
  this to prevent unintentional switching.

* turn off mouse driven virtual desktop switching on X windows.  it
  will interfere with synergy.  use keyboard shortcuts instead.

* synergy's screensaver synchronization works best with xscreensaver
  under X windows.  synergy works better with xscreensaver if it is
  using of the screensaver extensions.  prior to xscreensaver 4.0
  you can use `-mit-extension', `-sgi-extension', or `-xidle-extension'
  command line options to enable an extension.  starting with 4.0
  you must enable the corresponding option in your .xscreensaver file.