Subject: re: mkdir with trailing / (patch proposed)
From: None <firstname.lastname@example.org>
Date: 04/28/2002 23:09:48
Here is a link to The Single UNIX Specification Version 2. Which is 98% conformative to POSIX (as SUSv2). But I would not expect the behavior in this matter to have changed.
It talks about the dirname call.
Deriving from this I would assume POSIX accepts trailing slashes on a directory.