Grep – Show Lines Until Certain Pattern [Duplicate]

I am on Ubuntu 16.04 and I want to search files for let’s say “if” and I want to the output until “endif”. The file could look like this

if …
  SOME CODE
endif

I can do this with grep -A9 if my_file | grep -B9 endif. This doesn’t works if the “if” clause is larger than 9 and if several “if” clauses are in the same file and if the first grep command contains several “if” clauses. The option -m1 in the second grep doesn’t help. Nested “if” clauses can be ignored. Has somebody an idea, maybe not with grep?

Difference to How do I grep for multiple patterns on multiple lines?

1. The question asks for a solution with grep which is answered already in the question: grep -A9 if my_file | grep -B9 endif. The solution doesn’t work in my case but would work in the case of the other question.

2. The proposed grep solutions of the other question don’t work (with Ubuntu?): grep: ein nicht geschütztes ^ oder $ wird mit -Pz nicht unterstützt. which is something like grep: a not protected ^ or $ is not supported with -Pz. I use the following:

   root:/tmp# cat file
   Some text
   begin
   Some text goes here.  
   end
   Some more text 
   root:/tmp# grep -Pzo "^begin\$(.|\n)*^end$" file
   grep: ein nicht geschütztes ^ oder $ wird mit -Pz nicht unterstützt
   

3. The proposed solutions search only for pattern which start at the beginning of the line if I interpret the proposed solution correctly. Even if I remove ^ the command doesn't work.