Problem referencing structure elements by pointer

If the typedef is visible, that's fine -- you just need to call it "configurationOptions" (since that's the name you gave it in the typedef) instead of "struct configurationsOptions".

Edit to add: At this point, I would say, if you have most of your code referring to "struct configurationOptions" to not typedef it but make it a named struct; if it's just a few mentions, go ahead and change those mentions. There's no advantage either way (typedef vs. named struct), so do whatever causes the least amount of typing at this point.

Anonymous means it simply doesn't have a name - nothing more.
Again, remove the "struct" keyword because there is no struct named configurationsOptions. There is only something named configurationsOptions.
As long as you have a full declaration of the struct, you can do a sizeof on it.

Many thanks - all clear now and code working

I wouldn't recommend typedef'ing it the same as the struct name,

I tend to do, along with a lot of other people

Code:

typedef struct name_s
{

} name_t;

That way you know, name_t is a type, and name_s is a struct.

Note that there's nothing actually wrong with using the same name for the structure as you do for the typedef, it's just rather confusing.