De duplicate message in AWS SQS

dedup-sqs.sh

declare -A messages;
for i in {1..10000};
do
    msg=$(aws --region ap-southeast-2 sqs receive-message \
        --queue-url $1 \
        --max-number-of-messages 1);
    msgMd5=$(echo $msg | jq -r '.Messages[].MD5OfBody');
    msgId=$(echo $msg | jq -r '.Messages[].MessageId');
    if [ -n "${messages[$msgMd5]}" -a "${messages[$msgMd5]}" != "$msgId" ];
    then
        receiptHandler=$(echo $msg | jq -r '.Messages[].ReceiptHandle');
        aws --region ap-southeast-2 sqs delete-message \
            --queue-url $1 \
            --receipt-handle $receiptHandler;
        echo "Removing" $msgMd5;
    else
        messages[$msgMd5]=$msgId;
    fi;
done