Objective C on Windows using GNUStep - Part 1

One of the major hindrances in developing applications for iPhone is that the iPhone SDK is available only for the Mac OSX platform. Though there are some initiatives like objectiveclipse which are trying to bridge the gap, most of them are still in the conceptual stage.

Even though we still cant build iPhone applications on Windows yet, we can definitely sharpen our Objective C skills ( the language used for iPhone development ) without having to purchase a Mac.

Here I am going to show you how to develop Objective C applications on Windows using GNUStep. Part 1 of our journey for learning Objective C on Windows will only involve setting up GNUStep and compiling our first Objective C code. We will cover Objective C details in subsequent tutorials.

Download GNUStep:

* Go to the URL : http://www.gnustep.org/experience/Windows.html
* Download the latest version of following packages :
-> GNUSystem Version 0.23.0
-> GNUCore Version 0.23.1

Install GNUStep :

Just double click on the files to install. Admin rights on the machine is not required for installation.

* Install GNU System first.
* Install GNU Core. ( Note, Install Core only after you have installed System packages ).
* In order to run GNUStep, go to Start -> Programs -> GNUStep -> Shell

If you get the following shell, then you have successfully installed GNUStep and you are ready to start off with Objective C Programming.



Hello World using GNUStep.

* First let us write our Hello World program. I use notepad++ for writing my Objective C code. I find it simple, light weight and easy to use. You can use any editor of your choice.

* Create a file main.m

main.m :

#import <Foundation/Foundation.h>
int main(int argc, const char *argv[]) {
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
NSString *name = @"Hello World !";
NSLog(name);
[name release];
[pool release];
return 0;
}

* We are going to use 'make' file to build the this objective C code. Let us create a file called GNUmakefile. Please note that file names are case sensitive.

GNUmakefile :

include $(GNUSTEP_MAKEFILES)/common.make

APP_NAME = HelloWorld
HelloWorld_HEADERS =
HelloWorld_OBJC_FILES = main.m
HelloWorld_RESOURCE_FILES=

include $(GNUSTEP_MAKEFILES)/application.make

* Now navigate to the directory where you had saved these two files and type make. It should run the GNUmakefile and compile the Objective C code and create an executable.



* You can see that a directory HelloWorld.app has got created. This directory constitutes the application. This application can be executed using the following command

openapp ./HelloWorld.app



* This will write HelloWorld to the Windows Even Viewer. ( NSLog writes to the event viewer ). To navigate to the event viewer Start -> Control Panel -> Administrative Tools -> Event Viewer. The output will come under 'application' events.

This ends the small but important first step towards learning Objective C. In the next part, I 'll cover Objective C fundamentals.