[yencabulator]

I was going based on the theory of "5 characters plus leading underscore hits linker 6-character limit", but then this document talks about a system call named "execute".

If "execute" was really called "exec" in the source, then none of the syscall names I saw are longer than "creat".

[colejohnson66]

Except in this document, it's actually documented as "create" (with an 'e')

[yencabulator]

Maybe this document predates (discovery of) the linker limitation?

My understanding is that the linker didn't really limit the identifier length, it's just that only 6 characters were used to match them. So, shortening names create->create, execute->exec might have come afterward, as a clean up round to make it less surprising.

[colejohnson66]

That would make sense, but it's still speculation. Preferably, we'd be able to get a definitive answer from Mr. Thompson himself.