spell [-bilvx] [+ local_file] [file] ...
The spell command collects words from the named files and looks them up in a spelling list. Words that neither occur among nor are derivable (by applying certain inflections, prefixes, or suffixes) from words in the spelling list are written to the standard output.
If there are no file arguments, words to check are collected from the standard input. spell ignores most troff(1), tbl(1), and eqn(1) constructs. Copies of all output words are accumulated in the history file (spellhist), and a stop list filters out misspellings (for example, their=thy-y+ier) that would otherwise pass.
By default, spell (like deroff(1)) follows chains of included files (.so and .nx troff(1) requests), unless the names of such included files begin with /usr/lib.
The standard spelling list is based on many sources, and while more haphazard than an ordinary dictionary, is also more effective in respect to proper names and popular technical words. Coverage of the specialized vocabularies of biology, medicine and chemistry is light.
Three programs help maintain and check the hash lists used by spell:
The following options are supported:
The following operands are supported:
See environ(5) for descriptions of the following environment variables that affect the execution of spell: LC_CTYPE, LC_MESSAGES, and NLSPATH.
The following exit values are returned:
See attributes(5) for descriptions of the following attributes:
deroff(1), eqn(1), sort(1), tbl(1), troff(1), attributes(5), environ(5)
spell works only on English words defined in the U.S. ASCII codeset.
Because copies of all output are accumulated in the spellhist file, spellhist might grow quite large and require purging.
The spelling list's coverage is uneven. New installations might wish to monitor the output for several months to gather local additions.
British spelling was done by an American.