title: Under cygwin64 and gtk2, how to specify includes and libraries?
body: <p>I am using cygwin64 installed in C:/cygwin64, with eclipse and GTK2.0. Although <code>include &lt;gtk/gtk.h&gt;</code> is in the source, and C:/cygwin64/usr/include/gtk-2.0 is in the include path (I added it), many things in a gtk2 simple example are still not recognized, such as <code>GtkWidget</code>, <code>gpointer</code>, and <code>GTK_WINDOW_TOPLEVEL</code>. I got the whole of GTK2 via cygwin setup. I was and am reluctant to download all of GTK2 separately and install it on top of cygwin, since wouldn't it result in multiple locations for the same thing? How may I resolve it? Would separate download and installation not result in redundancy, and possible alternate or even conflicting aliases?</p>
  
  <p>A secondary question: I am confused about the general library requirements. Cygwin is a package which runs on Windows, but offers a Linux/unix-like interface. This argues that the libraries should be .a and .so. But since it is Windows, I also see a lot of .dll within C:\cygwin64. Normally, I would expect that only cygwin proper would contain .dll files and all other code would be Linux code. Yet that seems not to be the case. Often, I see both .dll and .so libraries with the same base name. Which is it, dll, or .so and .a, etc?     </p>
  
  <p>A tertiary question relating to the one above involves the main gtk2 library. The projected usage is not developing these programs, but just using GTK2 in applications. The documentation says to use glib, but there are many. Some are glib2.so, others glib2, or cygglib2.0.0.dll. Which of these is appropriate? or some other library? How do I set the exclipse LIBRARY path? (Since I unexpectedly encountered the problem with gtk.h, I am trying to anticipate and head off the corresponding problem with the library implementing gtk2.)</p>