What does "Ex" stand for in Windows API function names?

Maxim Gershkovich picture Maxim Gershkovich · Oct 28, 2010 · Viewed 11.5k times · Source

In windows APIs and various other libraries where I have seen multiple entry points to methods I have noticed the use of the Ex abbreviation in scenarios such as MyApiCall and MyApiCallEx.

My assumption is that this stands for Extension or Extra could someone please confirm?

Any history on why Ex was chosen rather then MyApiCall2 or similar would also be appreciated.

Answer

ssube picture ssube · Oct 28, 2010

I was under the impression it stood for extended, as in a more detailed interface for that particular library.

For example, CreateFile with 4 parameters is the typical version and CreateFileEx with 17 is the version offering more control and finer detail over how the file is opened, what occurs if it doesn't exist, etc, and is thus extended.