--- a/syslog_in_udp.c	Sun May 14 16:23:56 2006 +0200
+++ b/syslog_in_udp.c	Sun May 14 16:39:14 2006 +0200
@@ -8,7 +8,6 @@
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <stdbool.h>
-#include <netdb.h> // Per protoent getprotobyname
 #include <assert.h> // Per assert()
 #include <sys/select.h> // Pel select()
 
@@ -17,27 +16,9 @@
 
 #define LISTEN_QUEUE = 10;
 
-const bool ipv6enabled = true;
-
 void show_help(const char * restrict program)
 {
-	printf("Usage: %s <udp_port>\n", program);
-}
-
-
-int udp_proto_number()
-{
-	struct protoent *protocol;
-
-	/* Get the protocol udp number */
-	protocol = getprotobyname("udp");
-	if (protocol == NULL)
-	{
-		fprintf(stderr, "Cannot get the protocol number for udp.\n");
-		abort();
-	}
-	
-	return protocol->p_proto;
+	printf("Usage: %s <udp_port> (negative for enable ipv6)\n", program);
 }
 
 int listen_ipv6(int port)
@@ -49,7 +30,7 @@
 
 
 
-	socket_ipv6 = socket(PF_INET6, SOCK_DGRAM, udp_proto_number() );
+	socket_ipv6 = socket(PF_INET6, SOCK_DGRAM, 0);
 	if (socket_ipv6 == -1)
 	{
 		fprintf(stderr, "IPv6 socket failed.\n");
@@ -97,7 +78,7 @@
 	int on=1;
 
 
-	socket_ipv4 = socket(PF_INET, SOCK_DGRAM, udp_proto_number() );
+	socket_ipv4 = socket(PF_INET, SOCK_DGRAM, 0);
 	if (socket_ipv4 == -1)
 	{
 		fprintf(stderr, "IPv4 socket not supported.\n");
@@ -135,7 +116,7 @@
 	return socket_ipv4;
 }
 
-void server_loop(int port)
+void server_loop(const int port, const bool ipv6enabled)
 {
 	int socket_ipv6, socket_ipv4;
 	fd_set listen_sockets;
@@ -211,6 +192,7 @@
 int main(int argn, char **argv)
 {
 	int port;
+	bool use_ipv6 = false;
 
 	/* Processem els paràmetres d'entrada */
 	if (argn != 2) {
@@ -219,6 +201,14 @@
 	}
 
 	port=atoi(argv[1]);
+	/* If a port number is typed as negative, it will start
+	 * also the ipv6 server */
+	if(port < 0)
+	{
+		port = -port;
+		use_ipv6 = true;
+	}
+
 	if (port < 0 || port >65535)
 	{
 		show_help(argv[0]);
@@ -226,7 +216,8 @@
 	}
 
 	program_ignore_hup();
-	server_loop(port);
+
+	server_loop(port, use_ipv6);
 
 	return 0;
 }