curl 已经支持 HTTP2，使用方法如下

		
neo@MacBook-Pro ~/workspace % curl -I --http2 https://www.google.com  
HTTP/2 200 
date: Tue, 26 Feb 2019 06:36:03 GMT
expires: -1
cache-control: private, max-age=0
content-type: text/html; charset=ISO-8859-1
p3p: CP="This is not a P3P policy! See g.co/p3phelp for more info."
server: gws
x-xss-protection: 1; mode=block
x-frame-options: SAMEORIGIN
set-cookie: 1P_JAR=2019-02-26-06; expires=Thu, 28-Mar-2019 06:36:03 GMT; path=/; domain=.google.com
set-cookie: NID=160=aQySEvsSa9gVU8qivD3t5qsgi_PRUtD5Ao3nRb48jMyLAzlYA1ViWuF1BaZHChVzY6EuknQ0OUz3Z2vhWwrclzO4WV6BmWgPhz6jowqFF3XCStsyYVwLQp2-_c0aGioBryAP1bTT0c-PX9iJzk5Zcbm2cFs6kH0Qb2a_3ML7Ioc; expires=Wed, 28-Aug-2019 06:36:03 GMT; path=/; domain=.google.com; HttpOnly
alt-svc: quic=":443"; ma=2592000; v="44,43,39"
accept-ranges: none
vary: Accept-Encoding		
		
		

HTTP/2 200 表示当前采用 HTTP2 连接