替换 ed 中第二次出现的单词/短语

Question

仅替换 ed 中第二次/第三次出现的单词/短语的语法是什么？

He wanted to buy groceries from the shop, but preferred not having to go into the shop. >>
He wanted to buy groceries from the shop, but preferred not having to go into it. >>

Answer 1

ed, ,中的替换命令s///在命令字符串末尾采用零个或多个标志。如果标志包含正整数n，替代将作用于n: 第一场比赛。

假设您想the shop用 string 替换当前行上第二次出现的 substring it，您可以使用

s/the shop/it/2

编辑会话的快照可能如下所示，其中用户使用 来查看当前行，p然后决定对第二次出现的 进行更改the shop，在编辑后再次显示该行（使用p 旗帜命令的s///）：

p
He wanted to buy groceries from the shop, but preferred not having to go into the shop.
s/the shop/it/2p
He wanted to buy groceries from the shop, but preferred not having to go into it.

编辑命令的这一特点s///被继承了sed。