xplugd is a UNIX daemon that executes a script on X input and RandR changes, i.e., when a, keyboard, mouse. or a monitor is plugged in or unplugged. Useful in combination with lightweight setups, e.g. when running an X window manager like Awesome, Fluxbox, or similar to detect when docking or undocking a laptop.

xplugd [-hnpsv] [-l LEVEL] [FILE]

-h        Show help text and exit
-l LEVEL  Set log level: none, err, info, notice*, debug
-n        Run in foreground, do not fork to background
-p        Probe currently connected outputs and output EDID info.
-s        Use syslog, even if running in foreground, default w/o -n
-v        Show version info and exit

FILE       Optional script argument, default $XDG_CONFIG_HOME/xplugrc
           Fallback also checks for ~/.config/xplugrc and ~/.xplugrc

When FILE is omitted xplugd uses $XDG_CONFIG_HOME/xplugrc, if that cannot be found ~/.config/xplugrc is tried, and finally ~/.xplugrc. The file is called as a shell script on plug events as follows:

xplugrc TYPE DEVICE STATUS ["Optional Description"]
         |    |      |
         |    |       `---- connected or disconnected
         |     `----------- HDMI3, LVDS1, VGA1, etc.
          `---------------- keyboard, pointer, display

The script may be called like this, notice how the description is not included for displays:

xplugrc display HDMI3 disconnected
xplugrc keyboard 3 connected "Topre Corporation Realforce 87"

The keyboard or pointer is always the X slave keyboard or pointer, and the status encoding for XIStatusEnabled and XIStatusDisabled is forwarded to the script as connected and disconnected, respectively.

If EDID data is available from a connected display, the monitor model is passed in as fourth argument ("Optional Description") to the script.

#!/bin/sh
LAPTOP=LVDS1
DOCK=HDMI3
DESKPOS=--left-of
PRESPOS=--right-of

if [ "$1" != "display" ]; then
    case "$1,$3,$4" in
        pointer,conntected,"SynPS/2 Synaptics TouchPad")
            xinput set-prop $2 'Synaptics Off' 1
            ;;
        keyboard,connected,*)
            setxkbmap -option ctrl:nocaps
            ;;
    esac
    exit 0
fi

if [ "$3" = "disconnected" ]; then
    xrandr --output $2 --off
    exit 0
fi

if [ "$2" = "${DOCK}" ]; then
    xrandr --output $2 --auto --primary ${DESKPOS} ${LAPTOP}
elif  [ "$1" != "${LAPTOP}" ]; then
    xrandr --output $2 --auto ${PRESPOS} ${LAPTOP} --primary
else
    xrandr --auto
fi

To build xplugd you need the standard libraries and header files for X11, X11 input, and Xrandr. On a Debian/Ubuntu system these files can be installed with:

sudo apt install libx11-dev libxi-dev libxrandr-dev

Then run the configure script and make:

./configure && make

Unless building from the GIT sources, in which case ./autogen.sh first must be called to create the configure script. With relased tarballs this is not necessary.

To change the default installation prefix from /usr/local, use the

./configure --prefix=/some/other/path

Followed by

make all && sudo make install-strip

xplugd is composed from pieces of Stefan Bolte's srandrd and Andrew Shadura's inputplug. Please report bugs and problems to the xplugd project.