Compare s3 versions. "Stolen" from https://stackoverflow.com/q/40138780/395686

s3-compare-last-versions.sh

#!/bin/bash

# s3-compare-last-versions.sh

set -eu -o pipefail

if [[ $# -ne 2 ]]; then
    echo "Usage: `basename $0` <bucketName> <fileKey> "
    exit 1
fi

tmpdir="$(mktemp -d)" && trap 'rm -rf "${tmpdir:-/tmp/foo}"' EXIT QUIT INT

bucketName=$1
fileKey=$2

for v in 0 1; do
    VersionId=$(
        aws s3api list-object-versions \
           --bucket $bucketName \
            --prefix $fileKey \
            --max-items 2 \
            --output json \
            --query Versions[$v].VersionId
    )
    aws s3api get-object \
        --bucket $bucketName \
        --key $fileKey \
        --version-id \
        $VersionId ${tmpdir}/$v > /dev/null
done


${DIFFTOOL:-diff -Nur} ${tmpdir}/1 ${tmpdir}/0