S_ARCH1 / S_ARCH2 / strmode(3)

[Jan Schaumann <jschauma%netmeister.org@localhost>]

Hello,

Our ls(1) still supports (via strmode(3)) and
documents files of types

#define _S_ARCH1  0200000               /* Archive state 1, ls -l shows 'a' */
#define _S_ARCH2  0400000               /* Archive state 2, ls -l shows 'A' */

In over 25 years of using Unix systems day in, day
out, I have never encountered a file with an archive
state set.

OpenBSD, FreeBSD, macOS, and Linux don't seem to
support this file type.

Grepping through the entire NetBSD source tree, I only
see S_ARCH1 and S_ARCH1 defined and used in sys/stat.h
and strmode.c -- that is, I can't find anything
anywhere actually setting this flag.

(They were added in sys/sys/stat.h, r1.38,
lib/libc/string/strmode.c r1.9. back in 1999.)

Is this actually useful, or is this a remnant from who
knows when that nowadays could be removed?

-Jan