POSIX.1-2024 added the 'iflags=fullblock' option to 'dd'. This patch
documents that.
Although it is a part of POSIX, it is not widely supported. FreeBSD
added it in 2019, but NetBSD and OpenBSD do not support it
[1]. Therefore the portability warning can stay in place.
Will push in a bit.
[1]
https://github.com/freebsd/freebsd-src/commit/b52c534bffcc40e5be49f6d012c9d4005f0bbd81
>From f37b23dafb1ac79556ab1afa9c3f7917065fe108 Mon Sep 17 00:00:00 2001
Message-ID: <f37b23dafb1ac79556ab1afa9c3f7917065fe108.1750989070.git.collin.fu...@gmail.com>
From: Collin Funk <collin.fu...@gmail.com>
Date: Thu, 26 Jun 2025 18:48:51 -0700
Subject: [PATCH] doc: mention that POSIX.1-2024 added dd iflag=fullblock
* doc/coreutils.texi (dd invocation): Document that POSIX.1-2024 added
iflag=fullblock.
---
doc/coreutils.texi | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 865ceff05..8435d3543 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -9919,7 +9919,8 @@ @node dd invocation
@end table
-These flags are all GNU extensions to POSIX.
+These flags are all GNU extensions to POSIX, except for @samp{fullblock}
+which was added by POSIX.1-2024.
They are not supported on all systems, and @samp{dd} rejects
attempts to use them when they are not supported. When reading from
standard input or writing to standard output, the @samp{nofollow} and
--
2.50.0
