Re: [RFC v1] man/man2/close.2: CAVEATS: Document divergence from POSIX.1-2024

[Al Viro <viro@zeniv.linux.org.uk>]

On Fri, Jan 23, 2026 at 02:02:53AM +0100, Alejandro Colomar wrote:
> > HISTORY
> >        The close() system call was present in Unix V7.
> 
> That would be simply stated as:
> 
> 	V7.
> 
> We could also document the first POSIX standard, as not all Unix APIs
> were standardized at the same time.  Thus:
> 
> 	V7, POSIX.1-1988.
> 
> Thanks!

11/3/71							 SYS CLOSE (II)
NAME		close -- close a file
SYNOPSIS	(file descriptor in r0)
		sys	close		/ close = 6.
DESCRIPTION	Given a file descriptor such as returned from an open or
		creat call, close closes the associated file. A close of
		all files is automatic on exit, but since processes are
		limited to 10 simultaneously open files, close is
		necessary to programs which deal with many files.
FILES
SEE ALSO	creat, open
DIAGNOSTICS	The error bit (c—bit) is set for an unknown file
		descriptor.
BUGS
OWNER		ken, dmr

That's V1 manual.  In V3 we already get EBADF on unopened descriptor;
in _all_ cases there close(N) ends up with descriptor N not opened.