The code for MRI is.. idiomatic, but actually pretty easy to read. I last did C full time in the 90s and so am mostly just a 'reader' now but it's not hard to follow, although some of the reasoning behind doing things a certain way in MRI is unfathomable.. ;-)
Exactly, Peter. It's not tremendously hard to read the C code and understand what it is doing (usually), if you're familiar with C syntax. But it was tremendously difficult at times understanding _why_ it was doing what it was doing.