Compiling with MinGW and Initializing WinSock

Hello :D; Today, I'd like to explore the usage of MinGW in the context of building a simple program that utilizes an important library in the compilation process. This tutorial will help you use MinGW to build a basic program with the g++ command, teaching the purposes of some of the commands, and even exploring how to initialize WindowsSockets, or WinSock. Sockets are relevant to networking, and learning to work with them means learning how computers communicate through networks, with which much of our modern economy now depends. So learning how to initialize this library for use in you programming efforts will help considerably, and with networking becoming such a crucial aspect of programming any application in the modern world, it should be considered good knowledge as a programmer to know how a networking library works, and how to use one.

First, load up the console of your choice and move to a suitable directory, preferably an empty one. Make sure MinGW is installed; if not, please refer to my previous tutorial for an example installation of MinGW for Windows 7. From here, create a new cpp file with the following command : notepad newfile.cpp. This will open notepad and generate the filename your typed in, as a c++ file. Copy the following

#include <winsock2.h>

#include <ws2tcpip.h>

#include <stdio.h>

WSADATA wsaData;

int main () {

int iResult;

// Initialize Winsock

iResult = WSAStartup(MAKEWORD(2,2), &wsaData);

if (iResult != 0) {

    printf("WSAStartup failed: %d\n", iResult);

    return 1;

}

printf("WSAStartup Successful");

return 0;

}

This code simply creates a variable for holding the details of the WindowsSocket implementation being run, wsaData. That variable is called in the WSAStartup() method, and if unsuccessful, the program will output the “WSAStartup Failed” message and return from main, ending the run for the program. If the parameters are good for WSAStartup(), then the method will return a 0 to iResult and the if loop will conclude. From here, the program will output a “WSAStartup() Successful” message, then conclude the program with successful execution, by returning 0.

After the code above is in the .cpp file, save that file and close it. From here, Type in the following sequence:

g++ -Wall newfile.cpp –o programName.exe –lws2_32

This will produce a simple program from the supplied file from above. In this case, the above program will be as simple program that outputs a message, but depending on the results of that program, it might be an error message, or a successful initialization message for the Winsock library.

G++ : The C++ compiler installed with MinGW; this compiler and linker will create the program executable for us, and is key in accessing any of the other variables.

-Wall : A Preprocessor flag known as W-all, will enable all ‘W’ flags, enabling the compiler warnings and checks often found in Visual Studios.

newfile.cpp : Our source file that will be compiled for our program.

-o : Output files, which can be specified, as we have with the .exe suffix.

-l (-lws2_32) : This is a linker flag for compiling libraries with our program. In this case, the –l is indicating a library to link with, and WindowsSocket, or ws2_32 in our command line argument, indicating ws2_32.lib.

This should produce an executable for you to run in your own prompt, which should be enough of a program to output the successful initialization message in the command prompt.