Question

The function somefunction() takes a triple pointer as an argument.

int somefunction(tchar ***returnErrors); 

How to allocate memory for the returnErrors parameter?

Answer 1

At a guess . . .

You can think of returnErrors as a pointer to an array of strings.

1. The first * imples pointer to array of tchar (or a single string of tchars)
2. The second * imples a pointer to an array of strings.
3. The last * is so you can change returnErrors and pass back the new memory.

To delare memory for this (silly example, allocating memory inside SomeFunction)

tchar ** errors; // Oops it appears I need to pass back two error strings (+ 1 for null on end, so we know there are no more - thanks tlholaday) errors = malloc(sizeof(tchar*) * 3);  // the first string has length 20 (+ 1 for null terminator) errors[0] = malloc(sizeof(tchar) * 21);  // the second string has length 30 (+ 1 for null terminator) errors[1] = malloc(sizeof(tchar) * 31);  // ensure the last is null errors[2] = 0;  *returnErrors = errors; 

NB: The calling function needs to know that SomeFunction has allocated memory and needs to free it.