使用Sed将字符串变量替换为字符串变量

本文介绍了使用Sed将字符串变量替换为字符串变量的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有一个名为 ethernet 的文件，其中包含多行.我已将其中一行保存为名为 old_line 的变量.该变量的内容如下所示:

I have a file called ethernet containing multiple lines. I have saved one of these lines as a variable called old_line. The contents of this variable looks like this:

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="2r:11:89:89:9g:ah", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"

我创建了另一个名为 new_line 的变量，该变量与 old_line 类似，但在文本中进行了一些修改.

I have created a second variable called new_line that is similar to old_line but with some modifications in the text.

我想使用sed将 old_line 的内容替换为 new_line 的内容.到目前为止，我有以下内容，但不起作用:

I want to substitute the contents of old_line with the contents of new_line using sed. So far I have the following, but it doesn't work:

sed -i "s/${old_line}/${new_line}/g" ethernet

推荐答案

您需要转义oldline，以便它不包含正则表达式特殊字符，幸运的是，可以使用sed完成此操作.

You need to escape your oldline so that it contains no regex special characters, luckily this can be done with sed.

old_line=$(echo "${old_line}" | sed -e 's/[]$.*[\^]/\\&/g' ) sed -i -e "s/${old_line}/${new_line}/g" ethernet