#/bin/bash
# rmplaying.sh
# only works when exactly 1 instance of mplayer is running
function playing() {
  PID=`pidof mplayer`
  WHICH=`which mplayer`
  if [ $PID ]; then
    lsof -p $PID | awk '{ if ($5=="REG" && $4!="mem" && $9)print $9 }' | grep -v "$WHICH"
  fi
}

FILE=`playing`
if [ "$FILE" ]; then
  rm "$FILE" && echo "Removed '$FILE'"
fi

chmod +x rmplaying.sh

Ctrl+d run "/path/to/rmplaying.sh"

DEL run "rm '${path}'"