regex - 如何在 BASH 中查找和替换文件每一行的最后一个空格？

Question

我有这样一个文件:

Once upon a time there lived a cat.
The cat lived in the forest.
The forest had many trees.

我需要用“@”替换每行的最后一个空格，例如:

Once upon a time there lived a@cat.
The cat lived in the@forest.
The forest had many@trees.

我尝试了 sed 's/.*$/@/g' file.txt，但是 .* 匹配所有内容并删除了其中找到的所有文本。

如何用“@”替换每行的最后一个空格？

Answer 1

试试这个:

sed 's/\(.*\) /\1@/'