doc: reference detailed "numeric mode" info from chmod.1

Note were links are not supported (like on Solaris or FreeBSD),
the text still displays normally.

* man/chmod.x: Link from "numeric mode" in chmod man page,
to more detailed online info.

diff --git a/man/chmod.x b/man/chmod.x
index 39749f0bf82096494e73aa1e724138d465f32735..4a20c5b43f9c0ef382fe23fc7f0998e1db324cda 100644 (file)
--- a/man/chmod.x
+++ b/man/chmod.x
@@ -49,7 +49,9 @@ users who are members of the file's group (\fBg\fP),
 and the permissions granted to users that are in neither of the two preceding
 categories (\fBo\fP).
 .PP
-A numeric mode is from one to four octal digits (0\-7), derived by
+.ds cU https://www.gnu.org/software/coreutils/manual/html_node
+A \X'tty: link \*(cU/Numeric-Modes.html'\fBnumeric mode\fP\X'tty: link'
+is from one to four octal digits (0\-7), derived by
 adding up the bits with values 4, 2, and 1.  Omitted digits are
 assumed to be leading zeros.
 The first digit selects the set user ID (4) and set group ID (2) and