这个是截取access.log 21/Jul/2019:00:00:00 - 22/Jul/2019:00:00:04 的日志到access.log-2019-07-21
sed -n '/21\/Jul\/2019:00:00:00/,/22\/Jul\/2019:00:00:04/p' access.log > access.log-2019-07-21