Re: Meaning of file flags

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

Rocky Hotas <rockyhotas%firemail.cc@localhost> wrote:
 
>  <https://mail-index.netbsd.org/tech-security/1999/02/01/0000.html>
> 
> where short descriptions of flags are shown. However, I still can't
> understand the meaning of `nodump' and `arch'.
> Is there another reference/document/message about them?

Does the attached diff help?

If somebody could double-check that the 'arch' flag is
accurately described, then I'd commit this.

(I think the immutable and append-only flags are
self-explanatory and don't warrant being further
explained.)

-Jan

Index: chflags.1
===================================================================
RCS file: /cvsroot/src/usr.bin/chflags/chflags.1,v
retrieving revision 1.28
diff -u -p -r1.28 chflags.1
--- chflags.1	19 May 2023 19:50:59 -0000	1.28
+++ chflags.1	22 May 2023 22:43:13 -0000
@@ -32,7 +32,7 @@
 .\"
 .\"	@(#)chflags.1	8.4 (Berkeley) 5/2/95
 .\"
-.Dd May 19, 2023
+.Dd May 22, 2023
 .Dt CHFLAGS 1
 .Os
 .Sh NAME
@@ -104,6 +104,18 @@ The following keywords are currently def
 .It Li uchg Ta user immutable Ta owner or super-user
 .El
 .Pp
+The
+.Va arch
+flag is only used in connection with certain
+filesystems (e.g., MS-DOS), where it indicates whether
+a file has been modified since it was last backed up.
+.Pp
+A file with the
+.Va nodump
+flag set will by default only be backed up by
+.Xr dump 8
+during full backups.
+.Pp
 Putting the letters
 .Sq Cm no
 before a keyword causes the flag to be turned off.