The spell(1) utility compares words from one or more
files specified in file (or standard input if no files are
named) with those in a spelling list. It writes to standard output
all words that were not found on the list.
The spell(1) utility takes the following options:
Check against a British dictionary. The default dictionary is
American English. The British dictionary contains spellings such as
colour, behaviour, and recognise.
Write all words not in the spelling list. This is the default
behavior. Some implementations of spell(1) also check
against possible permutations of the words in the spelling list;
for those systems, this option turns off that behavior.
Display root stems of words as =.
Treat the words in the file local_dict as correctly spelled.
They will not appear in the spell(1) output. These words are
checked in addition to the usual dictionary file.