aplay loop

#!/bin/bash

if [ $# -lt 1 ];
then
 echo "enter a song name, format: wav, ex: happy.wav"
    exit
else
 echo "song name:$1"
fi

while true
do
    cmd=$( ps -ef | grep -v grep | grep -v $0 | grep $1 | awk '{print $2}')
    if [ "${cmd}" != "" ];
    then
        sleep 1
    else
        aplay $1 &
    fi
done