如何删除重复行但不排序（保持初始顺序）

How to remove repeated lines but not sorting (keep the initial order)

我有这个输入：

Host: ping.chartbeat.net
Host: extra.test.co
userblablabla
Host: extra.test.co
Host: extra.test.co
Host: extra.test.co
Host: extra.test.co
Host: extra.test.co
Host: extra.test.co
Host: extra.test.co
Host: extra.test.co
Host: secure.test.com
userlalalalala
Host: ping.chartbeat.net
Host: secure.test.com
Host: secure.test.com
Host: secure.test.com

我想把它转换成这样：

Host: ping.chartbeat.net
Host: extra.test.co
userblablabla
Host: secure.test.com
userlalalalala

我该如何执行该操作？

我尝试了 |sort -u 但这打破了我想要的行的顺序

您想使用 uniq <file>。 uniq is part of the GNU coreutils.