ttfb.sh

#!/bin/bash
# ./ttfb https://www.google.com ~/your-log-file.txt

function ttfb() {
    curl -o /dev/null \
         -H 'Cache-Control: no-cache' \
         -s \
         -w "%{time_connect} %{time_starttransfer} %{time_total}" \
         $1
}

echo $(date "+%Y-%m-%d %H:%M:%S") $1 $(ttfb $1) | tr '\n' ' ' | sed 's/$//g' >> $2