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Posts Tagged ‘udev’

Running a script on USB drive insertion

November 11th, 2009
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Before I even get into how to do this, be warned: this is a really bad idea unless you can ensure total physical access control to the machine. About the only place I’d ever use it is in a non-networked embedded system in a secure location. Its original intent is to handle loading of pictures onto a Linux-based digital photo frame.

So, you want to run a specific script on insertion of a USB drive. Here’s how to use udev to do it:

  1. Create /etc/udev/rules.d/99-usbhook.rules:
    ACTION=="add",KERNEL=="sd*", SUBSYSTEMS=="usb", ATTRS{product}=="Mass Storage", RUN+="/root/bin/usbhook %k"

    This will run “/root/bin/usbook”, passing it the device name as an argument, every time a USB Mass Storage device is plugged in.

  2. run udevcontrol reload_rules
  3. Create your usbhook script.
  4. Enjoy

Here is my usbhook script to copy all files from a USB mass storage disk to a specific location. It includes quite a bit of debugging, and also checks for the presence of a file called “foobarbaz.txt” on the device before copying the files over.

#!/bin/bash
 
# script to move over all files from a USB key
# when it is inserted into the system.
 
# should be called from a udev rule like:
#ACTION=="add",KERNEL=="sd*", SUBSYSTEMS=="usb", ATTRS{product}=="Mass Storage", RUN+="/root/bin/usbhook %k"
 
# Copyright 2009 Jason Antman. <jason@jasonantman.com> <http://www.jasonantman.com>
# <http://blog.jasonantman.com/2009/11/running-a-script-on-usb-drive-insertion/>
 
# CONFIGURATION
DEBUG=1 # set to 1 for debugging output
DEST="/home/foo/" # destination for files
 
 
DEVICE="$1" # the device name
LOGFACILITY="kernel.info" # for debugging output
 
 
if [ ${DEBUG:=0} == 1 ]; then logger "$LOGFACILITY" usbhook called with arguments: "$DEVICE"; fi
 
sleep 5 # delay 5 seconds to wait for mount
 
mount | grep "$DEVICE"
FOO="$?"
 
if [ $FOO == 0 ];
then
    if [ ${DEBUG:=0} == 1 ]; then logger "$LOGFACILITY" usbhook device mounted: "$DEVICE"; fi
else
    if [ ${DEBUG:=0} == 1 ]; then logger "$LOGFACILITY" usbhook device NOT mounted: "$DEVICE" - exiting; fi
    exit 0
fi
 
BAR=`mount | grep "$DEVICE" | awk '{ print $3 }'`
 
if [ -e "$BAR/foobarbaz.txt" ]
then
    if [ ${DEBUG:=0} == 1 ]; then logger "$LOGFACILITY" usbhook "$BAR"/foobarbaz.txt found; fi
else
    if [ ${DEBUG:=0} == 1 ]; then logger "$LOGFACILITY" usbhook "$BAR"/foobarbaz.txt NOT found - exiting; fi
    exit 0
fi
 
cp -R "$DEVICE"/* "$DEST"

This was tested on OpenSuSE 10.3.

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