add test for getaddrinfo

tests/test_getaddrinfo.c

@@ -0,0 +1,41 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+ 
+#ifndef   NI_MAXHOST
+#define   NI_MAXHOST 1025
+#endif
+ 
+int main(void) {
+	struct addrinfo *result;
+	struct addrinfo *res;
+	int error;
+	
+	/* resolve the domain name into a list of addresses */
+	error = getaddrinfo("www.example.com", NULL, NULL, &result);
+	if (error != 0)
+	{   
+		fprintf(stderr, "error in getaddrinfo: %s\n", gai_strerror(error));
+		return EXIT_FAILURE;
+	}   
+	
+	/* loop over all returned results and do inverse lookup */
+	for (res = result; res != NULL; res = res->ai_next)
+	{   
+		char hostname[NI_MAXHOST] = "";
+	
+		error = getnameinfo(res->ai_addr, res->ai_addrlen, hostname, NI_MAXHOST, NULL, 0, 0); 
+		if (error != 0)
+		{
+		fprintf(stderr, "error in getnameinfo: %s\n", gai_strerror(error));
+		continue;
+		}
+		if (*hostname != '\0')
+		printf("hostname: %s\n", hostname);
+	}   
+	
+	freeaddrinfo(result);
+	return EXIT_SUCCESS;
+}