C.2. hotplug: input.rc

#!/bin/bash
#
# input.rc	This loads handlers for those input devices
#		that have drivers compiled in kernel
#		Currently stopping is not supported
#
# Best invoked via /etc/init.d/hotplug or equivalent, with
# writable /tmp, /usr mounted, and syslogging active.
#


PATH=/sbin:/bin:/usr/sbin:/usr/bin
PROCDIR=/proc/bus/input

# source function library
if [ -f /etc/init.d/functions ]; then
	. /etc/init.d/functions
elif [ -f /etc/rc.d/init.d/functions ]; then
	. /etc/rc.d/init.d/functions
fi

if [ -f /etc/hotplug/hotplug.functions ]; then
	. /etc/hotplug/hotplug.functions
fi

input_reset_state () {

    PRODUCT=
    NAME=
    PHYS=
    EV=
    KEY=
    REL=
    ABS=
    MSC=
    LED=
    SND=
    FF=

}

#
# "COLD PLUG" ... load input handlers for compile-in input drivers loaded
# before the OS could really handle hotplug, perhaps because /sbin or
# $HOTPLUG_DIR wasn't available or /tmp wasn't writable.  When/if the
# /sbin/hotplug program is invoked then, hotplug event notifications
# get dropped.  To make up for such "cold boot" errors, we synthesize
# all the hotplug events we expect to have seen already.  They can be
# out of order, and some might be duplicates.
#
input_boot_events ()
{
    if [ ! -r $PROCDIR/devices ]; then
	    echo $"** can't synthesize input events - $PROCDIR/devices missing"
	    return
    fi

    ACTION=add
    export ACTION

    export PRODUCT NAME PHYS EV KEY REL ABS MSC LED SND FF
    input_reset_state

    declare line

    #
    # the following reads from /proc/bus/input/devices. It is inherently
    # racy (esp. as this file may be changed by input.agent invocation)
    # but so far input devices do not appear in sysfs
    #
    while read line; do
	case "$line" in
	    I:* )	# product ID
		eval "${line#I: }"
		PRODUCT=$Bus/$Vendor/$Product/$Version
	    ;;
	    N:* )	# name
		eval "${line#N: }"
		NAME="$Name"
	    ;;
	    P:* )	# Physical
		eval "${line#P: }"
		PHYS=$Phys
	;;
	    B:* )	# Controls supported
		line="${line#B: }"
		eval "${line%%=*}=\"${line#*=}\""
	    ;;
	    "" )	# End of block
		debug_mesg "Invoking input.agent"
		debug_mesg "PRODUCT=$PRODUCT"
		debug_mesg "NAME=$NAME"
		debug_mesg "PHYS=$PHYS"
		debug_mesg "EV=$EV"
		debug_mesg "KEY=$KEY"
		debug_mesg "REL=$REL"
		debug_mesg "ABS=$ABS"
		debug_mesg "MSC=$MSC"
		debug_mesg "LED=$LED"
		debug_mesg "SND=$SND"
		debug_mesg "FF=$FF"
		/etc/hotplug/input.agent < /dev/null
		input_reset_state
	    ;;
	esac
    done < $PROCDIR/devices
}


# See how we were called.
case "$1" in
  start)
	input_boot_events
        ;;
  stop)
	: not supported currently
        ;;
  status)
	echo $"INPUT status for kernel: " `uname -srm`
	echo ''

	echo "INPUT devices:"
	if [ -r $PROCDIR/devices ]; then
	    grep "^[INHP]:" $PROCDIR/devices
	else
	    echo "$PROCDIR/devices not available"
	fi
	echo ''

	echo "INPUT handlers:"
	if [ -r $PROCDIR/handlers ]; then
	    cat $PROCDIR/handlers
	else
	    echo "$PROCDIR/handlers not available"
	fi

	echo ''

	;;
  restart)
	# always invoke by absolute path, else PATH=$PATH:
	$0 stop && $0 start
	;;
  *)
        echo $"Usage: $0 {start|stop|status|restart}"
        exit 1
esac