[master] 76ab7d5 Document the use of UDS for -a addresses in man varnishd(1).

[Geoff Simmons]

commit 76ab7d588f4d739400849c42ea2dbfdad7529909
Author: Geoff Simmons <geoff at uplex.de>
Date:   Fri Feb 23 14:44:41 2018 +0100

    Document the use of UDS for -a addresses in man varnishd(1).

diff --git a/doc/sphinx/reference/varnishd.rst b/doc/sphinx/reference/varnishd.rst
index 7b1e3eb..c2c0c88 100644
--- a/doc/sphinx/reference/varnishd.rst
+++ b/doc/sphinx/reference/varnishd.rst
@@ -15,7 +15,7 @@ HTTP accelerator daemon
 SYNOPSIS
 ========
 
-varnishd [-a [name=][address][:port][,PROTO]] [-b host[:port]] [-C] [-d] [-F] [-f config] [-h type[,options]] [-I clifile] [-i identity] [-j jail[,jailoptions]] [-l vsl[,vsm]] [-M address:port] [-n name] [-P file] [-p param=value] [-r param[,param...]] [-S secret-file] [-s [name=]kind[,options]] [-T address[:port]] [-t TTL] [-V] [-W waiter]
+varnishd [-a [name=][address][:port][,PROTO][,user=<user>][,group=<group>][,mode=<mode>]] [-b host[:port]] [-C] [-d] [-F] [-f config] [-h type[,options]] [-I clifile] [-i identity] [-j jail[,jailoptions]] [-l vsl[,vsm]] [-M address:port] [-n name] [-P file] [-p param=value] [-r param[,param...]] [-S secret-file] [-s [name=]kind[,options]] [-T address[:port]] [-t TTL] [-V] [-W waiter]
 
 varnishd [-x parameter|vsl|cli|builtin|optstring]
 
@@ -36,14 +36,22 @@ OPTIONS
 Basic options
 -------------
 
--a <[name=][address][:port][,PROTO]>
+-a <[name=][address][:port][,PROTO][,user=<user>][,group=<group>][,mode=<mode>]>
 
   Listen for client requests on the specified address and port. The
   address can be a host name ("localhost"), an IPv4 dotted-quad
-  ("127.0.0.1"), or an IPv6 address enclosed in square brackets
-  ("[::1]"). If address is not specified, `varnishd` will listen
-  on all available IPv4 and IPv6 interfaces. If port is not specified,
-  port 80 (http) is used. At least one of address or port is required.
+  ("127.0.0.1"), an IPv6 address enclosed in square brackets
+  ("[::1]"), or a path beginning with a '/' for a Unix domain socket
+  ("/path/to/listen.sock"). If address is not specified, `varnishd`
+  will listen on all available IPv4 and IPv6 interfaces. If port is
+  not specified, port 80 (http) is used. At least one of address or
+  port is required.
+
+  If a Unix domain socket is specified as the listen address, then the
+  user, group and mode sub-arguments may be used to specify the
+  permissions of the socket file -- use names for user and group, and
+  a 3-digit octal value for mode. These sub-arguments are not
+  permitted if an IP address is specified.
 
   Name is referenced in logs. If name is not specified, "a0", "a1",
   etc. is used. An additional protocol type can be set for the