adding in sample code

scanner/main.cpp

@@ -0,0 +1,62 @@
+#include <cstdio>
+#include <dns_sd.h>
+
+void DNSSD_API serviceResolveCallback(
+    DNSServiceRef service, DNSServiceFlags flags, uint32_t interfaceIndex,
+    DNSServiceErrorType errorCode, const char *fullName, const char *hostTarget,
+    uint16_t port, uint16_t txtLen, const unsigned char *txtRecord,
+    void *context) {
+  if (errorCode == kDNSServiceErr_NoError) {
+    printf("Resolved Service: %s\n", fullName);
+    printf("Host: %s\n", hostTarget);
+    printf("Port: %u\n", ntohs(port)); // Convert the port to host byte order
+  } else {
+    printf("Failed to resolve service: %d\n", errorCode);
+  }
+}
+
+void DNSSD_API serviceBrowseCallback(
+    DNSServiceRef service, DNSServiceFlags flags, uint32_t interfaceIndex,
+    DNSServiceErrorType errorCode, const char *serviceName, const char *regtype,
+    const char *replyDomain, void *context) {
+  if (errorCode == kDNSServiceErr_NoError) {
+    printf("Service found: %s.%s%s\n", serviceName, regtype,
+           replyDomain ? replyDomain : "");
+
+    // Now resolve the service to get port and other details
+    DNSServiceRef resolveRef;
+    DNSServiceErrorType resolveError =
+        DNSServiceResolve(&resolveRef, 0, interfaceIndex, serviceName, regtype,
+                          replyDomain, serviceResolveCallback, nullptr);
+
+    if (resolveError != kDNSServiceErr_NoError) {
+      printf("Error resolving service: %d\n", resolveError);
+    } else {
+      // Process the resolved service
+      DNSServiceProcessResult(resolveRef);
+      DNSServiceRefDeallocate(resolveRef);
+    }
+  }
+}
+
+int browseServices() {
+  DNSServiceRef serviceRef;
+  DNSServiceErrorType error = DNSServiceBrowse(
+      &serviceRef, 0, 0, "_flowy._tcp", NULL, serviceBrowseCallback, NULL);
+
+  if (error != kDNSServiceErr_NoError) {
+    fprintf(stderr, "Error browsing services: %d\n", error);
+    return -1;
+  }
+
+  // Process the mDNS service (this will block until services are discovered)
+  DNSServiceProcessResult(serviceRef);
+
+  DNSServiceRefDeallocate(serviceRef);
+  return 0;
+}
+
+int main() {
+  browseServices();
+  return 0;
+}