Bash retry with exponential backoff

with_backoff.sh

function with_backoff {
    local max_attempts=${ATTEMPTS-5}
    local timeout=${TIMEOUT-1}
    local attempt=1
    local exitCode=0

    while [[ ${attempt} -lt ${max_attempts} ]]; do
        "$@"
        exitCode=$?

        if [[ ${exitCode} == 0 ]]; then
            break
        fi

        echo "Retrying in ${timeout} seconds..." 1>&2
        sleep "${timeout}"
        attempt=$((attempt + 1))
        timeout=$((timeout * 2))
    done

    if [[ ${exitCode} != 0 ]]; then
        echo "Failure after maximum number of retry attempts" 1>&2
    fi

    return ${exitCode}
}

Usage: with_backoff curl http://kdjaskdjkasjda.com