ngctl: Modernize code somewhat

[des]

Summary

• Replace fgets(3) with getline(3)

• Replace select(2) with poll(2)

• Avoid needlessly copying text around

• Correct use of getopt(3)

• Pick some style and whitespace nits

MFC after: 1 week

[kevans]

Tentatively seems fine, I'll do another pass tomorrow

usr.sbin/ngctl/main.c

149

This one was technically fine - style(9) allows more restrictive scoping these days, but I guess if that's not really applied anywhere else in this file we might as well push it up.

[markj]

usr.sbin/ngctl/main.c

149

It's used elsewhere in this file. I'd rather keep variables locally scoped when possible.

602

Indentation is wrong here.

[des]

update

[des]

more

[des]

usr.sbin/ngctl/main.c

149

If you agree that style(9) allows both then please allow me to prefer the old style. It also saves vertical space by not requiring an additional blank line.

[markj]

usr.sbin/ngctl/main.c

149

And locally scoped variables reduce cognitive load when reading, by keeping declarations close to uses. But this is all subjective. The point of a style guide is to enforce some level of consistency, not to optimize for any particular metric like vertical space used. Our guide permits both styles, so here you're not fixing a bug but changing code to suit personal preferences. I prefer that we not make changes like that: they pollute git blame output and give reviewers extra things to check for no real benefit. But ok, I'm not insisting, I clicked the accept button.