Added check for number of arguments

main.c

@@ -3,6 +3,7 @@
 #include <unistd.h>
 #include <stdlib.h>
 #include "easysock.h"
+#define PROG_NAME "basicproxy"
 
 void forward_data(int from_fd, int to_fd) {
 	int n = 0;
@@ -24,6 +25,10 @@ int check_ip_ver(char* address) {
 }
 
 
+void print_prog_info() {
+	printf("%s - [Local IP address] [local port] [remote IP address] [remote port]\n",PROG_NAME);
+}
+
 int main(int argc,char* argv[]) {
 
 /* argv[1] = local address
@@ -31,6 +36,12 @@ int main(int argc,char* argv[]) {
    argv[3] = remote address
    argv[4] = remote port */
 
+	if (argc != 5) {
+		print_prog_info();
+		exit(-30);
+	}
+
+
 	char* local_addr = argv[1];
 	int local_port = strtol(argv[2],NULL,10);
 	char* remote_addr = argv[3];