rrdupdate(1): Document the RRDCACHED_ADDRESS environment variable.

diff --git a/doc/rrdupdate.pod b/doc/rrdupdate.pod
index c0705d4..d61cf12 100644 (file)
--- a/doc/rrdupdate.pod
+++ b/doc/rrdupdate.pod
@@ -69,8 +69,8 @@ instead of accessing the files directly. If I<address> begins with C<unix:>
 then everything after this prefix will be considered to be a UNIX domain
 socket, see L<EXAMPLES> below. Otherwise the address is interpreted as network
 address or node name as understood by L<getaddrinfo(3)>. One practical
-consequence is that both, IPv4 and IPv6, may be used if the system supports it.
-This option is available for the B<update> command only.
+consequence is that both, IPv4 and IPv6, may be used if the system supports
+it. This option is available for the B<update> command only.
 
 =item B<N>|I<timestamp>B<:>I<value>[B<:>I<value>...]
 
@@ -98,6 +98,21 @@ separator.
 
 =back
 
+=head1 ENVIRONMENT VARIABLES
+
+The following environment variables may be used to change the behavior of
+C<rrdtoolE<nbsp>update>:
+
+=over 4
+
+=item B<RRDCACHED_ADDRESS>
+
+If this environment variable is set it will have the same effect as specifying
+the C<--daemon> option on the command line. If both are present, the command
+line argument takes precedence.
+
+=back
+
 =head1 EXAMPLES
 
 =over 4