Anvils from orbit. It’s the only way to be sure.
In a fairly recent version of a commercial Linux system, the copy of cpio (which is, of course, FSF tentacleware) has a fairly awful manpage which shows the command line options, a few paragraphs describing how it works, and a long list of the options (including the utterly loathsome word options that the FSF -- an organization where nobody actually does any coding, I guess -- adores,) but no examples, authors, crossreferences, or bugs sections like you'd find in any well-written manpage. It's not a very good manpage, but this is a FSF product, so any sort of documentation, even if it hasn't been changed in *13* years, is better than nothing.
But this fairly recent version of the operating system isn't the most recent version. In the most recent version, they've changed the manpage to the much more useful:
GNU cpio is fully documented in the texinfo documentation. To access
the help from your command line, type
info cpio
The online copy of the documentation is available at the following
address:
http://www.gnu.org/software/cpio/manual
It's not as if manpages are some new and radical thing here. If there's anything that's standard about Unix, manpages are standard because they've been around since basically the beginning of time. But, no, here's the goddamn Free Software Foundation making their own stupid utilities less useful so they can beat the drum for their awful proprietary documentation format that has nothing going for it except that there's apparently a special emacs®©™ mode that makes the stinking format marginally bearable.
And this from an organization that *leaps* upon new and dubious standards, crams them into their libc and cc (which isn't actually a C compiler unless you tell it to ignore the tentacleware extensions,) then foists them off on the world with a prissy "Well! That's what the *standard* says and we must obey the standard!"
Tell you what. When the FSF sinks their info format "documentation" to make an artificial reef off the coast of Massachusetts, then maybe I'll believe them when they do their standards©-based kabuki act.
I'll be over here fixing the manpages you've "improved" in your attempt to be the B-list Microsoft. Don't mind the stack of unlinked inodes; I was just tidying up /usr/share/info with a bulk tape eraser.
UPDATE: Nroff is just so much fun. There's nothing quite like spending the day formatting FSF "documentation" back into nroff format.