如何编写RegEx插入行长超过30个字符的换行符？

Question

我正在使用文本编辑器，它使用regular expression来查找/替换文本。我有一个很大的文本文件。我想在每个超过30个字符的行中插入新行。我希望线条在30个字符后断开（如果一个单词/短语不成立，则无关紧要）。

例子：

原始文本：

Hi this is a sample text. 
this is a line. 
This is a very very very very very long line. 
This is a regular line. 
.... 

修改后的文本：

Hi this is a sample text. 
this is a line. 
This is one very very very ver 
y very long line. 
This is a regular line. 
.... 

现在，我怎么能写regular expression换

1. 找出超过30个字符的行。
2. 在长度超过30个字符的行的第30个字符后面插入新行。

Answer 1

查找内容：

^(.{30}) 

替换为：

\1\n 

Answer 2

你可以试试这个兄弟.........检查这个的jsfiddle http://jsfiddle.net/elviz/wL7ob8ox/1/

var txt1 = "This is a very very very very very long line." 

    var txt2 = txt1.slice(0, 30) + " \n" + txt1.slice(30); 

    alert(txt2);