status=`curl -o /dev/null -s -m 5 -w %{size_download}:%{http_code}:%{time_total}:%{time_connect}:%{size_header}:%{time_namelookup} $url`
curl -o /dev/null -s -w connect:%{time_connect}-transfer:%{time_starttransfer}-total:%{time_total} http://xx
curl -o /dev/null -m 5 -s -w %{size_download} www.xx.com
-m 5 :超时设置为5秒
-m/--max-time <seconds> Maximum time allowed for the transfer
-w/--write-out [format] What to output after completion