Command
QisLib_GetStructureList

Purpose

Function:
	int QisLib_GetStructureList(char*** StructListPtr);

Inputs:
	StructListPtr: Address of pointer of type char**. When the function returns
	successfully, this pointer will point to a list of cell names.

Return:
	success: value > 0 indicating the number of cell names in the list
	failure: value <= 0 indicating one of the following errors :

Errors:
	0: No cells found, either no GDSII/OASIS file opened or invalid file.
	-1: Input argument is invalid (null).
	-2: No GDSII or OASIS file has been opened.
	-3: Internal memory error occurred while generating list of cell names.
	-4: File open in progress, operation not permitted.

Description:
	- Gets a list of all cell names present in the file.
	- There could be many cells in the file (hundreds of thousands or even more). It is
	the responsibility of the user program to ensure that the memory allocated for the
	list is freed by a call to QisLib_FreeStructureList().
	- The order of the cell names in the list is the order in which they are first
	referenced or defined in the GDSII/OASIS file.
	- This function should not be called while a file open is in progress.

Example:
	char** List;
	Ret = QisLib_GetStructureList(&List);
	...
	...
	if(Ret > 0)
	QisLib_FreeStructureList(List,Ret);