如何在 BASH 中查找并替换文件每一行的最后一个空格？

Question

我有一个这样的文件：

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.

我尝试过sed 's/ .*$/@/g' file.txt，但.*匹配所有内容并删除在那里找到的所有文本。

如何用“@”替换每行最后一个空格？

Answer 1

尝试这个：

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