Re: [gdm-list] custom display on gdmgreeter

[Yan Seiner <yan seiner com>]

Ishaaq Chandy wrote:
> Good idea - but unfortunately that doesn't work unless you are logged in:
>
> ~$ export DISPLAY=:0
> ~$ notify-send "foo" "bar"
> libnotify-Message: Unable to get session bus: dbus-launch failed to 
> autolaunch D-Bus session: No protocol specified
> Autolaunch error: X11 initialization failed.
Not that simple.  You need to get the session stuff.  I'm attaching a 
script I wrote that writes to arbitrary X sessions.

Not sure if that will word as-is, but if you look at the end you'll see 
how I handle the authentication.

--Yan

> Ishaaq
>
> 2009/4/6 Yan Seiner <yan seiner com <mailto:yan seiner com>>
>
>     Ishaaq Chandy wrote:
>
>         Hi all,
>
>         My wife uses an external USB hard-disk to maintain her photo
>         gallery. She needed a simple way to backup this disk. I've
>         setup one of my linux installs' udev configuration to detect
>         when this particular disk gets connected to its USB port and
>         then kicks off my custom script which mounts the drive, rsyncs
>         her photo gallery to a backup disk and then unmounts the drive
>         when done.
>
>         This works beautifully, no hassles. The problem is, there is
>         no feedback that this is happening, nor is there any
>         indication when it is completed and the hard disk can be
>         safely removed. I was wondering if there is some way I can
>         hack into the gdm greeter for it to show up an icon (and
>         possibly a progress bar - but that may be ambitious) when the
>         disk is being rsynced.
>
>         My wife isn't very computer savvy, which is why I want to make
>         this very simple from her point of view. I on the other hand
>         am not afraid to write some C/C++ to get this working. As long
>         as someone can give me some pointers as to where to start.
>
>         ... or tell me I'm barking up the wrong tree and that GDM
>         can't do this.
>
>     I don't know if notify-send works when gdm is running, but that
>     would be a start.....
>
>     --Yan
>
>     -- 
>     Yan Seiner
>     Support my bid for the 4J School Board.
>     Visit http://www.seiner.com/schoolboard
>
>
>
> !DSPAM:49d983b6274111061887518!
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>   


--
Yan Seiner 

Support my bid for the 4J School Board.
Visit http://www.seiner.com/schoolboard


#!/bin/sh

USAGE="$0 -s summary -u user -t timeout -p priority -i icon -c category -h help -v version message"

pids=`pgrep '[gnome|xfce4|kde]-session'`

# title
# user
# timeout
# urgency
# icon
# category
# help
# version

line=''

while getopts s:u:m:t:p:c:i:hv OPT; do
    case "$OPT" in
	s)	title=$OPTARG ;;
	u)	user=$OPTARG 
		pids=`pgrep -u $user '[gnome|xfce4|kde]-session' 2>/dev/null ` || exit 1
		;;
	t)	timeout=$((OPTARG+0)) 
		line="$line -t $timeout"
		;;
	p)	priority=$OPTARG 
		line="$line -u $priority"
		;;
	i)	icon="$OPTARG" 
		line="$line -i \'$icon\'"
		;;
	c)	category=$OPTARG
		line="$line -c $category"
		;;
	h)	echo $USAGE
		exit 0
		;;
	v)	echo "`basename $0` version 0.1"
		exit 0
		;;
	\?)	# getopts issues an error message
		echo $USAGE >&2
		exit 1
		;;
    esac
done

shift `expr $OPTIND - 1`

message=$@

if [ -z "$message" ]; then
#	echo $USAGE
	exit 1
fi
if [ -z "$timeout" ]; then
        line="$line -t 60000"
fi

for pid in $pids; do
        # find DBUS session bus for this session
        DBUS_SESSION_BUS_ADDRESS=`grep -z DBUS_SESSION_BUS_ADDRESS \
                /proc/$pid/environ | sed -e 's/DBUS_SESSION_BUS_ADDRESS=//'`
	UNAME=`grep -z USERNAME \
		/proc/$pid/environ | sed -e 's/USERNAME=//'`
        DISP=`grep -z DISPLAY \
                /proc/$pid/environ | sed -e 's/DISPLAY=//'`
	XAUTH=`grep -z XAUTHORITY \
                /proc/$pid/environ | sed -e 's/XAUTHORITY=//'`

        # use it
echo $line
        DISPLAY=$DISP DBUS_SESSION_BUS_ADDRESS=$DBUS_SESSION_BUS_ADDRESS XAUTHORITY=$XAUTH \
        sudo -u $UNAME notify-send $line "$title" "$message"
done