如何查找和替换方括号之间出现的项目与sed？

Question

我正在使用sed来查找和替换文件中的某些项目，如下所示：

    sed -i "s/$a/$b/g" ./file.txt

我需要限制此查找和替换仅当匹配文本位于方括号之间时，例如：

The sheep lived in the barn.
One day, [the sheep ate some] grass.
The [sheep] found a nice place to sleep under the tree.
Afterwards, [the sheep ate apples under] the tree [near the barn].
The sheep [enjoyed the theme] of the movie.

假设$a设置为“the”而$b设置为“B”，输出将如下所示：

The sheep lived in the barn.
One day, [B sheep ate some] grass.
The [sheep] found a nice place to sleep under the tree.
Afterwards, [B sheep ate apples under] the tree [near B barn].
The sheep [enjoyed B theme] of the movie.

• 打开和关闭方括号始终显示在同一行。

如何找到并替换那些出现在sed方括号之间的项目？

Answer 1

你可以试试这个，

sed -i.bak -r "s#(\[[^]]*)$a( [^[]*\])#\1$b\2#g" ./file.txt