priv
CatPositionRec structure
#include <Files.h>
typedef struct CatPositionRec { Size Offset Description
long initialize; 4 0 starting point
short priv[6]; 12 4 private data

Notes: To start a search at the beginning of the catalog, set the initialization field
to 0. When it exits because of a timeout, PBCatSearch updates the record
so that it describes the next entry to be searched. When you call
PBCatSearch to resume the search after a timeout, pass the entire
record that was returned by the last call.PBCatSearch returns a list of the
names and parent directories of all files and directories that match the
criteria you specify. It places the list in an array pointed to by the
FSSpecPtr field. The array contains FSSpec records.