Use memcpy instead of strncpy when we know the length anyway. Modern gcc seems to think it knows how to detect misuse of strncpy, but it's wrong (in fact: very, very wrong) and the path of least resistance is to not try to fight with it.

[
  disregard ws
]

file $
  -> thing, eof

thing
  -> '[', "blah ", ']'
  -> word

word
  -> letter
  -> word, letter

ws
  -> space + tab

letter = 'a-z'
space = ' '
tab = '\t'
eof = '\n'