Add -R option to rigctld to close the rig when no clients are connected

The FT-736 has to lock the rig for CAT control so this allows it to unlock when rigctld is idle
https://github.com/Hamlib/Hamlib/issues/1117

doc/man1/rigctld.1

@@ -372,6 +372,10 @@ option as it generates no output on its own.
 Sets password on rigctld which requires hamlib to use rig_set_password and rigctl to use \\password to access rigctld.  A 32-char shared secret will be displayed to be used on the client side.
 .
 .TP
+.BR \-R ", " \-\-rigctld_idle
+Will make rigctld close the rig when no clients are connected.  Normally remains connected to speed up connects.
+.
+.TP
 .BR \-h ", " \-\-help
 Show a summary of these options and exit.
 .

tests/rigctld.c

@@ -83,7 +83,7 @@
  *      keep up to date SHORT_OPTIONS, usage()'s output and man page. thanks.
  * TODO: add an option to read from a file
  */
-#define SHORT_OPTIONS "m:r:p:d:P:D:s:S:c:T:t:C:W:w:x:z:lLuovhVZMA:n:"
+#define SHORT_OPTIONS "m:r:R:p:d:P:D:s:S:c:T:t:C:W:w:x:z:lLuovhVZMA:n:"
 static struct option long_options[] =
 {
     {"model",           1, 0, 'm'},
@@ -112,6 +112,7 @@ static struct option long_options[] =
     {"multicast-addr",  1, 0, 'M'},
     {"multicast-port",  1, 0, 'n'},
     {"password",        1, 0, 'A'},
+    {"rigctld-idle",    0, 0, 'R'},
     {0, 0, 0, 0}
 };
 
@@ -261,6 +262,7 @@ int main(int argc, char *argv[])
     int twiddle_timeout = 0;
     int twiddle_rit = 0;
     int uplink = 0;
+    int rigctld_idle = 0; // if true then rig will close when no clients are connected
     char host[NI_MAXHOST];
     char serv[NI_MAXSERV];
     char rigstartup[1024];
@@ -306,6 +308,10 @@ int main(int argc, char *argv[])
             printf("rigctl %s\n", hamlib_version2);
             exit(0);
 
+        case 'R':
+            rigctld_idle = 1;
+            break;
+
         case 'A':
             strncpy(rigctld_password, optarg, sizeof(rigctld_password) - 1);
             //char *md5 = rig_make_m d5(rigctld_password);
@@ -762,7 +768,11 @@ int main(int argc, char *argv[])
     rig_debug(RIG_DEBUG_VERBOSE, "Backend version: %s, Status: %s\n",
               my_rig->caps->version, rig_strstatus(my_rig->caps->status));
 
-#if 0
+    // Normally we keep the rig open to speed up the 1st client connect
+    // But some rigs like the FT-736 have to lock the rig for CAT control
+    // So they need to release the rig when no clients are connected
+    if (rigctld_idle)
+    {
         rig_close(my_rig);          /* we will reopen for clients */
 
         if (verbose > RIG_DEBUG_ERR)
@@ -771,8 +781,7 @@ int main(int argc, char *argv[])
                my_rig->caps->rig_model,
                my_rig->caps->model_name);
         }
-
+    }
-#endif
 
 #ifdef __MINGW32__
 #  ifndef SO_OPENTYPE
@@ -1405,6 +1414,7 @@ void usage(void)
         "  -M, --multicast-addr=addr     set multicast UDP address, default 0.0.0.0 (off), recommend 224.0.1.1\n"
         "  -n, --multicast-port=port     set multicast UDP port, default 4532\n"
         "  -A, --password                set password for rigctld access\n"
+        "  -R, --rigctld-idle            make rigctld close the rig when no clients are connected\n"
         "  -h, --help                    display this help and exit\n"
         "  -V, --version                 output version information and exit\n\n",
         portno);