Add info key 'i' to show some states.

Currently showing C-Netz attached subscribers

src/common/main.h

@@ -39,3 +39,5 @@ void sighandler(int sigset);
 
 void main_loop(int *quit, int latency, int interval, void (*myhandler)(void));
 
+void dump_info(void);
+

src/common/main_common.c

@@ -329,6 +329,10 @@ next_char:
 			/* toggle display */
 			display_wave_on(-1);
 			goto next_char;
+		case 'i':
+			/* dump info */
+			dump_info();
+			goto next_char;
 		}
 
 		/* process audio of built-in call control */