Place the rows of two blocks of text after each other alternatively

Question

I have the following two blocks of text

abc
abc
cdz
zer
sdf



bfd
dss
azr
vvf
ezr

I want to know how I can place the rows of these two blocks alternatively so that I get the final block of text as following:-

abc
bfd
abc
dss
cdz
azr
zer
vvf
sdf
ezr

Answer 1

Using macro to move 1 line at a time:

1. Start recording macro with your cursor on the 1st char of the 1st line
2. Move cursor down x lines until the first line of the 2nd block (x=8 in this case)

   8j
   

3. Cut this line using D instead of dd to maintain the distance between the 2 blocks

   D
   

4. Move cursor up x lines to the first line

   8k
   

5. Paste the line we just cut

   o[esc]p
   

6. Move cursor to the next starting position (1st char of the next line)

   j^
   

7. End recording.
8. Replay this macro on each line.

Answer 2

Here is a method inspired by this question:

1. Write each block to a separate temporary file:

   vip
   :'<,'>w /tmp/a
   <motion>
   vip
   :'<,'>w /tmp/b
   

2. Cut the two blocks.

3. Insert the output of paste:

   :read !paste -d '\n' /tmp/a /tmp/b