Hi, Vincent: >>you didn't quoted everything or read carefully: **If** you do Ah yup :)...sorry I didn't read this carefully. This makes what Peter said feasible in my opinion i.e we could set errno to 0 and thereby the loop will only be processed once and we can make do with the #ifdef at the point. For *ix platforms errno will be set in the case of an error and the code should function normally. Will make the change and test out the code. Jamey: >>Looks like _xcb_open on Win32 could fall off the end without defining a >>return value. Have you compiled this with warnings turned on? Yes _xcb_open should have a return value. Will make the change. Bye for now <div class="gmail_quote">On Thu, Apr 1, 2010 at 10:07 AM, Vincent Torri <<a href="mailto:vtorri@univ-evry.fr">vtorri@univ-evry.fr</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div class="im"> On Thu, 1 Apr 2010, Jeetu Golani wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Hi, <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Fine with me, but I thought there were platforms where you can't assign to errno--in fact, I thought Win32 was one of those platforms? </blockquote> While mingw doesn't seem to complain if we assign errno = 0, this article on msdn suggests applications can't (or maybe shouldn't?) <a href="http://msdn.microsoft.com/en-us/library/ms737828%28VS.85%29.aspx" target="_blank">http://msdn.microsoft.com/en-us/library/ms737828(VS.85).aspx</a> <Quote> Furthermore, it is not possible for an application to assign a new value to errno. (In Windows Sockets, the function WSASetLastError may be used for this purpose.) </Unquote> </blockquote> </div> you didn't quoted everything or read carefully: **If** you do #define errno WSAGetLastError() then you can't set a value to errno as it's not an lvalue anymore. errno is a global variable and can, of course, be set if no strange define like above is done if you use socket functions on Windows, WSASetLastError() and WSAGetLastError() should be used to set / get errors, like errno for CRT Vincent </blockquote></div>