Lethbridge Linux User Group - Automatic USB icon for xtdesktop

LinuxGuru writes "The real point of this is the power of bash and how to use it to restart a program. I was in need of a way to restart a program for any user on any desktop so this is what I did.

So Bob is running some program on his desktop. The program has locked up and Bob asks root restart it. Sure root can kill the program but how can root start it up again and put it on Bob's desktop as if Bob ran the program? That was the problem I had.

I am working with a Linus Distro of my own flavor built from Debian and Knoppix. I am using icewm for the desktop and Xtdesk to give it icons. I wanted my USB memory stick have an icon that shows up when the USB drive is plugged in and remove the icon when it is un-plugged.

This simple bash script is an example of how I am able to use hotplug to restart the xtdesk application on any users desktop.

My first problem is that the hotplug scripts are running as the root user. The hotplug scripts are run when there is an event with the system. I don't know much about hotplug but I think you can do almost anything you want with a script when an event happens.

For this project I used icewm but you can use any desktop you like. Xfce, blackbox, windowmaker are all great desktops in need of icons.

Xtdesk uses a local directory in the users HOME to contain the configs for xtdesk and each icon. xtdesk only reads the icon config files when it first starts up. Any changes you make to the config files will not show until the next time it is started. For my configuration of xtdesk I am using a common directory /etc/X11/xtdesktop and every user has a symbolic link in their home that points to that. In that directory I created a new icon for my USB drive called usbmedia.lnk.hide. xtdesk will read all config files that end in lnk so I added the hide suffix to hide this config file from xtdesk. This is the normal state of the USB memory stick, un-plugged.

The first script I had to edit my hotplug script. Your system will most likely have different locations and names for your scripts but these are mine

File name: /etc/hotplug/usb/usb-storage # ---- BEGIN #!/bin/sh . /etc/hotplug/hotplug.functions if [ ! -L /var/run/usb/%proc%bus%usb%* ]; then mesg Try to Mount if [ ! -d /mnt/usbstorage ]; then mkdir /mnt/usbstorage fi # It takes a second for the module to finish loading sleep 1 NOT_MOUNTED=1 mount -t ext2 -o user,exec,sync /dev/sda /mnt/usbstorage > /tmp/hotplug.log 2>&1 NOT_MOUNTED=$? if [ $NOT_MOUNTED -ne 0 ]; then mount -t ext2 -o user,exec,sync /dev/sda1 /mnt/usbstorage > /tmp/hotplug.log 2>&1 NOT_MOUNTED=$? fi if [ $NOT_MOUNTED -ne 0 ]; then mount -t vfat -o user,exec /dev/sda /mnt/usbstorage > /tmp/hotplug.log 2>&1 NOT_MOUNTED=$? fi if [ $NOT_MOUNTED -ne 0 ]; then mount -t vfat -o user,exec /dev/sda1 /mnt/usbstorage > /tmp/hotplug.log 2>&1 NOT_MOUNTED=$? fi if [ $NOT_MOUNTED -eq 0 ]; then cp /etc/X11/xtdesktop/usbmedia.lnk.hide /etc/X11/xtdesktop/usbmedia.lnk xtdesk.restart ln -s /etc/hotplug/usb/usb-storage.off $REMOVER mesg make REMOVER in $REMOVER fi fi # ---- END If you read this script you will see that it tests for vfat and ext2 formated UBS memory sticks that are /dev/sda or /dev/sda1 devices and then mounts the device.

If the device was mounted then the usbmedia.lnk.hide config file is copied to usbmedia.lnk and the xtdesk.restart script is called.

And now for the cool part.

File name: /usr/bin/xtdesk.restart # ---- BEGIN #!/bin/bash RESTART_USER_ID=`id -u` PRG_CMD="false" ALL_XT_PIDS=`ps -C xtdesk|grep xtdesk|gawk '{print $1}'` for EACH_PID in $ALL_XT_PIDS; do ENVIRON_VALUES=`cat /proc/$EACH_PID/environ | tr "

Note: These scripts are licesnsed under the GNU GPL."