usbmon-setperms

#!/bin/sh
# helper for allowing the developer to read usbmon as non-root.

if [ "$USER" = "root" ]; then
    echo "Please run as regular user or set USER"
    exit 1
fi

GROUP="$(id -g)"
if [ $GROUP = 0 ]; then
    GROUP="$(id -g "$USER")"
fi

if [ ! -e /dev/usbmon0 ]; then
    echo "Attempting to modprobe usbmon..."
    sudo modprobe -v usbmon
    if [ ! -e /dev/usbmon0 ]; then
        echo "Cannot locate 'usbmon' kernel module"
        exit 1
    fi
fi

usbmons=$(lsusb -d046d: | cut -c7 | sed 's,^,/dev/usbmon,' | sort -u)

echo Found devices: $usbmons

usbmonsw=
for dev in $usbmons; do
    if [ ! -r "$dev" ]; then
        usbmonsw="$usbmonsw $dev"
    fi
done

if [ -n "$usbmonsw" ]; then
    echo "Attempting to make $usbmonsw readable"
    sudo chgrp -v $GROUP $usbmonsw
    sudo chmod -v g+r $usbmonsw
else
    echo "No devices found"
fi