[OxLUG] Online book called "Root" or something like that I c…

Years ago someone mentioned a book simply called "Root" (verbally) which
was ancient but had been placed online and was good for brushing up on
long forgotten command line and text editing skills etc. from the early
days of Unix. I can't find this in any search. Was it called something
else or spelt in some odd way (clever dicks with a play on words and
spellings are one of the banes of unix historically...) that I can't
remember.

Anyone recall what this was called or spelt as?

Thanks
Malcolm