如何編寫RegEx插入行長超過30個字符的換行符？

Question

我正在使用文本編輯器，它使用regular expression來查找/替換文本。我有一個很大的文本文件。我想在每個超過30個字符的行中插入新行。我希望線條在30個字符後斷開（如果一個單詞/短語不成立，則無關緊要）。

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. 
.... 

修改後的文本：

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. 
.... 

現在，我怎麼能寫regular expression換

1. 找出超過30個字符的行。
2. 在長度超過30個字符的行的第30個字符後面插入新行。

Answer 1

查找內容：

^(.{30}) 

替換爲：

\1\n 

Answer 2

你可以試試這個兄弟.........檢查這個的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);