sed add match +N to next line

Shell Programming and Scripting
1

Hi all,

I got some data in this format

A: a b c dA: e f g hA: i j k lA: m n o p

Could someone please help me out to get ti in this format ?

A: a b c d
A: e f g h
A: i j k l
A: m n o p

I'd like to match A: and move it in the line below

Thank you very much

2 
echo 'A: a b c dA: e f g hA: i j k lA: m n o p' | sed 's/.:/\n&/g' | sed '/^$/d'
3

With two capture groups and back-references one can insert a newline in the middle:

sed 's/\(.\)\(.:\)/\1\
\2/g'

Here I used the standard backslash-newline to represent the newline.