Access to structures defined in C

[Joe via Digitalmars-d-learn]

What is the correct way to declare and access storage managed by 
C?

For example, say a C module defines an array of filenames, e.g.,
char *files[] = { "one", "two", "three", 0};

The C header of course declares this as:

extern char *files[];

The way to declare it in a D module appears to be:

extern (C) {
   __gshared extern char *[] files;
}

However, trying to index into this, e.g.,

char *filename = files[1];

does not work.  In gdb if I try to examine 'filename' I see 
something like a reverse text string but treated as an 
(inaccessible) address and calling fromStringz causes a segfault.