替换常规换行和unicode换行

Question

我有带有段落格式的文本，date总是在每一段文章的前面。问题是，在每一篇文章之后，都会出现不同类型的unicode换行。我需要删除每个段落之间的每一个断行实例，并将其替换为两个\n\n。

所以从这个

05/12
The 1959 Mexico hurricane was a devastating tropical cyclone
that was one of the worst ever Pacific hurricanes. It 
impacted the Pacific coast of Mexico in October 1959. The
hurricane killed at least 1,000 people.




11/01
The 1959 Mexico hurricane was a devastating tropical cyclone
that was one of the worst ever Pacific hurricanes. It 
impacted the Pacific coast of Mexico in October 1959. The
hurricane killed at least 1,000 people.

到这个

05/12
The 1959 Mexico hurricane was a devastating tropical cyclone
that was one of the worst ever Pacific hurricanes. It 
impacted the Pacific coast of Mexico in October 1959. The
hurricane killed at least 1,000 people.

11/01
The 1959 Mexico hurricane was a devastating tropical cyclone
that was one of the worst ever Pacific hurricanes. It 
impacted the Pacific coast of Mexico in October 1959. The
hurricane killed at least 1,000 people.

我试过使用preg_replace()，但并不是每个实例都匹配吗？

$text = preg_replace('/\r?\n+(?=\d{2}\/\d{2})/', "\n\n", $text);

Answer 1

大约一个月前，我在一个类似的question上发布了这篇文章。

要匹配任何被认为是行中断序列的内容，可以使用\R

R匹配一个通用换行符；也就是说，任何被Unicode认为是换行序列的东西。这包括\v (垂直空格)匹配的所有字符和多字符序列\x0D\x0A。

试试这个吧。

$text = preg_replace('~\R+(?=\d{2}/\d{2})~u', "\n\n", $text);

请参阅有关实现此功能的不同方法的PCRE文档。