Use this gist to copy an object from one bucket to another from bash

s3copy.sh

s3key=your key
s3secret=your secret


function putS3
{
	object=$1
	sourceBucket='bucket'
	destinationBucket='bucket'
	date=$(date +"%a, %d %b %Y %T %z")
	string="PUT\n\n\n$date\nx-amz-copy-source:/$sourceBucket/$object\n/$destinationBucket/$object"
	echo "$string"
	signature=$(echo -en "${string}" | openssl sha1 -hmac "${s3secret}" -binary | base64)
	echo "$signature"
	curl -X PUT \
	 -H "Host: $destinationBucket.s3.amazonaws.com" \
	 -H "Date: $date" \
	 -H "x-amz-copy-source: /$sourceBucket/$object" \
	 -H "Authorization: AWS ${s3key}:$signature" \
	 "https://$destinationBucket.s3.amazonaws.com/$object"
}

putS3 "your object"