Mine

#!/bin/bash

SYS_DEVICE="/sys/bus/pci/drivers/ipw2200/0000:02:06.0/rf_kill"

OSDCAT_BIN=`which osd_cat`
#OSDCAT_FONT="-f -microsoft-comic sans ms-*-r-*-*-48-*-*-*-*-*-iso8859-15"
OSDCAT_FONT="-f -*-lucida-*-r-*-*-24-*-*-*-*-*-*-*"
OSDCAT_PARAM="-p bottom -o -40 -A center -i5 -s1 -d3 -c green"


OSDCAT_PIDFILE="/tmp/wlan_osd-$USER.pid"

check_wlan_status()
{
 test -f "$SYS_DEVICE" || {
  echo "Fehlgeschlagen, Treiber nicht geladen!"
  exit 1
 }

 rfkill_val=`cat "$SYS_DEVICE"`
 test $rfkill_val = "0" && echo "Aktiviert" || echo "Deaktiviert"
}

run_osd()
{
 test -f "$OSDCAT_PIDFILE" && . $OSDCAT_PIDFILE
 test -z $OSDCAT_PID || kill $OSDCAT_PID

 check_wlan_status|$OSDCAT_BIN $OSDCAT_PARAM "$OSDCAT_FONT" &
 OSDCAT_PID_=$!
 echo -n "OSDCAT_PID=$OSDCAT_PID_" >"$OSDCAT_PIDFILE"
 wait

 . $OSDCAT_PIDFILE
 test "$OSDCAT_PID_" = "$OSDCAT_PID" && rm -f "$OSDCAT_PIDFILE"
}

case $1 in
 run_osd)
  shift
  run_osd
 ;;

 *)
  test -x "$OSDCAT_BIN" || exit 1
  exec 0>&-
  exec 1>&-
  exec 2>&-
  $0 run_osd $* &
  exit 0
 ;;
esac

exit 0