Save a screenshot of the Windows desktop in .bmp format unsing only the Windows API.
The image will be saved as "screenshot.bmp" in the current working directory.

All linker dependencies are specified explicitly, so you can compile
screenshot-simple.exe by simply running:
   cl screenshot-simple.c

To compile with GCC run:
   gcc -Wall -Wextra -pedantic -O3 screenshot-simple.c -s -static -o screenshot-simple.exe -lgdi32

License: UnLicense (public domain) - <http://unlicense.org/>

For an advanced version that requires C++ see https://github.com/darealshinji/cmdline-screenshot-tool