Import spell(1) and deroff(1) from OpenBSD

[gbe]

Summary

spell(1) collects words from the named documents 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 printed
on the standard output.

deroff(1) reads each file in sequence and removes all roff
command lines, backslash constructions, macro definitions,
eqn constructs (between “.EQ” and “.EN” lines or between
delimiters), pic pictures, and table descriptions and writes
the remainder to the standard output.

spell(1) and deroff(1) did not appear in freely redistributable
BSD releases for licensing reasons. After Caldera relicensed early
UNIX releases the 4.4BSD version was added to NetBSD and OpenBSD.

MFC after: 2 weeks

Test Plan

buildworld

[mjg]

is there really use for it in base instead of as a port? especially the deroff thing is kind of... niche

[pauamma_gundo.com]

In D38768#882357, @mjg wrote:

is there really use for it in base instead of as a port? especially the deroff thing is kind of... niche

Per spell(1), spell uses deroff, so you can't have just spell in base.

usr.bin/deroff/deroff.1

64

Is the date left deliberately unchanged (including the $...$ tag) here and not in spell.1 below?

[gbe]

In D38768#882357, @mjg wrote:

is there really use for it in base instead of as a port? especially the deroff thing is kind of... niche

The spell(8) command is useful for spellchecking man pages, since the mdoc macros are very similar. I always find the usage of aspell on man page a pure pain to use. This is where deroff comes in.

I could make this a port and put the sources on GitHub, if an import into base should be avoided, but since NetBSD and OpenBSD ship it per default, why we shouldn't.

[gbe]

Landed as a port.