pactl: add format flag for JSON output

Part-of: <https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/merge_requests/497>

man/pactl.1.xml.in

@@ -53,6 +53,12 @@ License along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
       <optdesc><p>Choose the server to connect to.</p></optdesc>
     </option>
 
+    <option>
+      <p><opt>-f | --format</opt><arg>=FORMAT</arg></p>
+
+      <optdesc><p>Choose output format, available options are "text" or "json".</p></optdesc>
+    </option>
+
     <option>
       <p><opt>-n | --client-name</opt><arg>=NAME</arg></p>
 
@@ -63,7 +69,7 @@ License along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
 
   <section name="Commands">
     <p>
-        When supplied as arguments to the commands below, the special names \@DEFAULT_SINK@, \@DEFAULT_SOURCE@ and \@DEFAULT_MONITOR@ 
+        When supplied as arguments to the commands below, the special names \@DEFAULT_SINK@, \@DEFAULT_SOURCE@ and \@DEFAULT_MONITOR@
         can be used to specify the default sink, source and monitor respectively.
     </p>
 

src/pulsecore/json.c

@@ -650,6 +650,16 @@ static pa_json_context_type_t json_encoder_context_pop(pa_json_encoder *encoder)
     return type;
 }
 
+bool pa_json_encoder_is_empty(pa_json_encoder *encoder) {
+    pa_json_context_type_t type;
+
+    pa_assert(encoder);
+    pa_assert(encoder->context);
+
+    type = encoder->context->type;
+    return type == PA_JSON_CONTEXT_EMPTY;
+}
+
 pa_json_encoder *pa_json_encoder_new(void) {
     pa_json_encoder *encoder;
 

src/pulsecore/json.h

@@ -71,6 +71,8 @@ void pa_json_encoder_free(pa_json_encoder *encoder);
 /** Convert pa_json_encoder to string, free pa_json_encoder structure.
  * The returned string needs to be freed with pa_xree(). \since 15.0 */
 char *pa_json_encoder_to_string_free(pa_json_encoder *encoder);
+/** Check if a pa_json_encoder is empty (nothing has been added). \since 16.0 */
+bool pa_json_encoder_is_empty(pa_json_encoder *encoder);
 
 /** Start appending JSON object element by writing an opening brace. \since 15.0 */
 void pa_json_encoder_begin_element_object(pa_json_encoder *encoder);