除了遇到两个连续的新行以外,如何为每两行插入一个新行？

Question

我试图为每两行文本插入一个新行,除非我想在遇到新段落(连续两行)时重新启动此模式.(我想要的输出不应该有三个连续的新行.)

例如,这是我的输入文本:

This is my first
line to appear in
the text.

I need the second
line to appear in
the way that follows
the pattern specified.

I am not sure if
the third line will
appear as I want it
to appear because sometimes
the new line happens where
there are two consecutive 
new lines.

这是我想要的输出:

This is my first
line to appear in

the text.

I need the second
line to appear in

the way that follows
the pattern specified.

I am not sure if
the third line will

appear as I want it
to appear because sometimes

the new line happens where
there are two consecutive

new lines.

我试过用awk:

    awk -v n=2 '1; NR % n == 0 {print ""}'

但是此命令在新段落后不会重新启动模式.相反,我会从上面的示例文本中获得以下输出:

This is my first
line to appear in

the text.


I need the second

line to appear in
the way that follows

the pattern specified.


I am not sure if
the third line will

appear as I want it
to appear because sometimes

the new line happens where
there are two consecutive

new lines.

由于这个不需要的输出显示,没有重新启动模式,我将得到三个连续新行的实例.

Answer 1

perl中的段落模式可以帮助:

perl -00 -ple 's/.*\n.*\n/$&\n/g'

产量

This is my first
line to appear in

the text.

I need the second
line to appear in

the way that follows
the pattern specified.

I am not sure if
the third line will

appear as I want it
to appear because sometimes

the new line happens where
there are two consecutive 

new lines.

基于@Borodin评论:

perl -00 -ple 's/(?:.*\n){2}\K/\n/g'