curl find the response time code example
Example 1: curl measure time
curl -w "\n\n%{time_option}\n" www.google.com
http_code The numerical response code that was found
in the last retrieved HTTP(S) or FTP(s) transfer.
time_appconnect The time, in seconds, it took from the start until
the SSL/SSH/etc connect/handshake to the remote host
was completed.
time_connect The time, in seconds, it took from the start until
the TCP connect to the remote host (or proxy) was
completed.
time_namelookup The time, in seconds, it took from the start until the name
resolving was completed.
time_pretransfer The time, in seconds, it took from the start until the
file transfer was just about to begin.
time_starttransfer The time, in seconds, it took from the start until the first
byte was just about to be transferred.
time_total The total time, in seconds, that the full operation lasted.
Example 2: get current time curl
$ date -s `curl -I 'https://google.com/' 2>/dev/null | grep -i '^date:' | sed 's/^[Dd]ate: //g'`