Write header to stdout target.

adsbus/opts.c

@@ -2,6 +2,7 @@
 #include <string.h>
 #include <unistd.h>
 
+#include "buf.h"
 #include "incoming.h"
 #include "outgoing.h"
 #include "peer.h"
@@ -97,6 +98,17 @@ bool opts_add_stdout(char *arg) {
 	if (!serializer) {
 		return false;
 	}
-	send_new(dup(1), serializer, NULL);
+	int fd = dup(1);
+	{
+		// TODO: move into standard location for non-socket fd handling
+		struct buf buf = BUF_INIT, *buf_ptr = &buf;
+		send_hello(&buf_ptr, serializer);
+		if (buf_ptr->length) {
+			if (write(fd, buf_at(buf_ptr, 0), buf_ptr->length) != (ssize_t) buf_ptr->length) {
+				return false;
+			}
+		}
+	}
+	send_new(fd, serializer, NULL);
 	return true;
 }