systemd/debian/extra/logger.agent

#!/bin/sh -e
#
# log the event to a file
#

cd /lib/udev/
. ./hotplug.functions

# provide env-like output when the real thing is not available
if [ ! -x /usr/bin/env ]; then
    env() {
        # bash prepends "declare -x " at the beginning of each line
        export -p | sed -e 's/^\(declare -x\|export\) //'
    }
fi

# writes a copy of the current hotplug event to stdout
log_to_stdout()
{
    {
	echo "HOTPLUG_TIME='$(date)'"
	env
	echo ''
    } | egrep -v "^'$|^(_|PATH|PWD|PPID|SHLVL|HOME|IFS|OPTIND|PS[1234])="
}

[ "$EVENTS_LOG" ] || EVENTS_LOG='/dev/hotplug.log'

log_to_stdout >> $EVENTS_LOG

exit 0