Implementation of getdelim
Good job!

A few notes:


It is better to check for a malloc error right away instead of going to another function to check. Just like what you did with realloc.
Your function read_until_deliminator
returns an error but your implementation never checks for this error return
value.
I will do separation of concern, where you will obtain the input and find the delimiter in different functions. This is just to aid in code maintenance so it helps with readability for you and others.


I will post my changes later in the day.