conf: New option --show-socket.

* tools/gpgconf-comp.c (gc_component_t): Move this enum to ...
* tools/gpgconf.h: here.
* tools/gpgconf.c (oShowSocket): New.
(opts): Add new option.
(main): Implement new option.
--

This is a convenience options for software which directly connects to
gpg-agent and thus needs to new the socket.  By using --show-socket
along with --launch that software can also autostart the agent or the
dirmngr.  Without this two calls to gpgconf would be required.

Actually the same behaviour can be achieved by running
gpg-connect-agent to query the running gpg-agent's socket via GETINFO.
The gpg-connect also makes sure that the agent is started.  This is
not anymore suggested because gpgconf shall in future be used for all
such things.

Signed-off-by: Werner Koch <wk@gnupg.org>
(cherry picked from commit ac485b4f25)

tools/gpgconf.h

@@ -43,6 +43,34 @@ void gpgconf_failure (gpg_error_t err) GPGRT_ATTR_NORETURN;
 
 /*-- gpgconf-comp.c --*/
 
+/* Component system.  Each component is a set of options that can be
+ * configured at the same time.  If you change this, don't forget to
+ * update GC_COMPONENT in gpgconf-comp.c.  */
+typedef enum
+  {
+    /* The classic GPG for OpenPGP.  */
+    GC_COMPONENT_GPG,
+
+    /* The GPG Agent.  */
+    GC_COMPONENT_GPG_AGENT,
+
+    /* The Smardcard Daemon.  */
+    GC_COMPONENT_SCDAEMON,
+
+    /* GPG for S/MIME.  */
+    GC_COMPONENT_GPGSM,
+
+    /* The LDAP Directory Manager for CRLs.  */
+    GC_COMPONENT_DIRMNGR,
+
+    /* The external Pinentry.  */
+    GC_COMPONENT_PINENTRY,
+
+    /* The number of components.  */
+    GC_COMPONENT_NR
+  } gc_component_t;
+
+
 /* Initialize the components.  */
 void gc_components_init (void);