This page has examples for using the HotPlug package.

If your problem is just the "too sensitive touchpad," the best solution is to install a touchpad driver:

If you use GNOME 2.6 or later, you can install and run gnome-volume-manager, which can do things like run a program when a camera is plugged in, or mount a removable storage device when plugged in.


"Usermap" files

Newer versions of hotplug have a set of "usermap" files in /etc/hotplug/usb. (Older versions of hotplug use a single file named "/etc/hotplug/usb.usermap".) This gives the name of scripts to run for particular USB devices.

The file format is
name_of_script fields_to_match field1 field2 field3 ... field11

The "fields_to_match" field is a bitfield - add 1 if you want to match against field1, add 2 if you also want to match against field2, add 4 to match against field3, etc. Only field1 and field2 are really necessary - they correspond to vendor_id and vendor_product_id respectively.

Here is my usb.usermap:

 # kodak dx3900 digital camera
 usbcam          0x0003 0x040a 0x0170 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0
 # sony dsc p10 digital camera
 usbcam          0x0003 0x054c 0x004e 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0
 # laser printer
 brother_hl1440  0x0003 0x04f9 0x000d 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0

So, when a USB device with vendor ID of 40a and product ID of 170 is inserted, hotplug will run the script named "usbcam" in the /etc/hotplug/usb directory. The 0x0003 tells hotplug to match this rule against only the vendor ID (1) + the product ID (2), ignoring all the other fields. These flags are defined in /etc/hotplug/usb.agent . You can determine the values for your device by looking at your system logs (eg run dmesg(8)) after inserting the USB device. If you have the "usbutils" package installed, you could look in the file "/usr/share/misc/usb.ids" or run the "lsusb" command to get a description of connected USB devices.

See below for notes about the scripts.

Notes about editing the usb.usermap file

In the version of hotplug in Debian Woody, you should add your changes to /etc/hotplug/usb.usermap.local and then run

 # update-usb.usermap

In more recent versions of hotplug, (such as Debian Testing/Unstable), create files named /etc/hotplug/usb/{foo}.usermap, for each script you have named foo.

USB scripts

Make sure these scripts are executable! Hotplug will set the following environment variables for use by the scripts:

 ACTION {add, remove}
 DEVICE {name of the usbdevfs device... for example /proc/bus/usb/001/003}

See the /etc/hotplug/usb.agent script for more details.

Note that many of the script names in .../usb.distmap are actually module names.

Example scripts

This is the script run when hotplug detects one of the digital cameras. the gphoto2 package for DigitalCameras comes with its own usbcam script for this purpose, but it sets the USB device to be owned by the user that owns /dev/console, which doesn't work under debian. This works fine assuming you are the only person on your computer, or you trust the other users not to delete your photos from your camera :p.

Note - you probably don't need to do this manually any more... most distributions probably do this for you. Eg Debian Sarge and Sid, and Ubuntu now (libgphoto2-2 ver 2.1.4-8, Nov 2004) have a script that lets people in the 'camera' group access the device -- JohnMcPherson


 # John - we need to make the usb device readable/writeable by normal
 # users. Should be the same person as on console, but debian doesn't
 # change /dev/console to the current user, so make it world +rw.
 chmod a+rw "$DEVICE"

I'm not entirely sure that this really needs to be done every time, but I have noticed that sometimes CUPS can't talk to the printer if it is powered on after boot. Also see CUPSNotes to see where this command line came from.


  foomatic-configure -s cups -n Brother -c file:/dev/usb/lp0 -p Brother-HL-1440 \
  -d     hl1250 -o PageSize=A4

Disabling the touchpad when a USB mouse is added

1. I re-compiled the kernel so that PS/2 mouse support (psmouse.ko) is a module rather than compiled in.
2. Get UDev to create a symlink for the PS/2 touchpad. Eg: Create /etc/udev/rules.d/mouse.rules:

BUS="usb", KERNEL="mouse[0-1]", NAME="input/%k" SYMLINK="input/usbmouse"
# for psmouse (synaptic touchpad)
KERNEL="mouse[0-1]" NAME="input/%k" SYMLINK="input/touchpad"

3. get Xfree/Xorg to use /dev/input/mice as the core pointer, of type IMPS/2. All mice on the system send events via /dev/input/mice as well as each individual /dev/input/mouse<n> device. Add a secondary mouse that points to /dev/input/touchpad.
4. Set up a hotplug script that disables the touchpad when a usb mouse is added. Note! I had to comment out "usbmouse" from /etc/hotplug/blacklist otherwise hotplug ignores usb mouse events! /etc/hotplug/usb/usbmouse.usermap:

# el cheapo optical usb scroll mouse:
usbmouse        0x03    0x09da  0x0006 0 0 0 0 0 0 0 0 0



# this removes the psmouse.ko kernel module for the touchpad when a
# usb mouse is plugged in, and re-inserts the module when the usb mouse
#is removed.

if test "$ACTION" = "add"  ; then
    rmmod psmouse
    if test -n "$REMOVER" ; then
        # usb.agent sets this variable to point to an executable that
        # will be run on remove, if it exists
        ln -s "$0" "$REMOVER"
elif test "$ACTION" = "remove" ; then
    modprobe psmouse
# else unknown action?

I'm using kernel 2.6.12 and the module name is usbhid not usbmouse. I had the touchpad working already so all I needed to do was, comment out usbmouse from /etc/hotplug/blacklist and add the above script as /etc/hotplug/usb/usbhid then do a chmod +x /etc/hotplug/usb/usbhid.


By default, HotPlug in Debian (testing/unstable at least as of July 2004) won't automatically configure network interfaces.

In /etc/default/hotplug, there is a variable named NET_AGENT_POLICY (obsolete as of Aug 5, 2005) that can be set to "all", "auto", or "hotplug", with hotplug being the default. This refers to which entries in /etc/network/interfaces should be handled by hotplug.

My laptop's /etc/network/interfaces file includes the following lines:

 # use DHCP for the pccard network card
 iface eth0 inet dhcp
 # for the hotplug package
 mapping hotplug
    script echo
    map eth0

I use the hotplug package to configure automaticaly my WLAN card with the following entries (It's an USR 5411 so I use the ndsiwrapper driver) :

 mapping hotplug
 iface wlan0 inet dhcp
 pre-up wpa_supplicant -B -Dndiswrapper -iwlan0 -c/etc/wpa_supplicant.conf
 pre-down killall wpa_supplicant