Hello, Windows!

The Simplest Win32 Program You Will Ever See

Perhaps not, but the following code is probably the simplest Win32 program that it is possible to write. Follow the link to see the code.

You can build that program using the following sequence of commands (assuming you have saved the code as a file called simple.c):

gcc -c -o simple.o simple.c
gcc -o simple.exe simple.o -mwindows

Did that give you any trouble? If so:

Did you forget the -mwindows option? That option links in a set of standard Win32 libraries and also makes the program a "GUI" program (i.e. a program with windows) instead of a "console" program (i.e. a command-line based program). If you forget -mwindows this is what happens (the stuff before the simple.c will probably differ, but the last bit will be the same):

> gcc -c -o simple.o simple.c
> gcc -o simple.exe simple.o
simple.o(.text+0x2a):simple.c: undefined reference to `MessageBoxA@16'

Are you using a different version of gcc which doesn't support -mwindows? EGCS for Cygwin, and other versions of gcc, may not support the -mwindows option directly. Try this instead:

gcc -c -o simple.o simple.c
gcc -o simple.exe simple.o -luser32 -Wl,--subsystem,windows

This is a longer and more complex example which creates a window with a button in it.

You can compile that program like this

gcc -c -o test.o test.c
gcc -o test.exe test.o -mwindows

the same way as simple.c above. If your compiler doesn't support -mwindows try this:

gcc -c -o test.o test.c
gcc -o test.exe test.o -luser32 -lgdi32 -Wl,--subsystem,windows