#include <cat.h>
int cat_peekfilter(cat_session *session, int level, cat_filter *filter);
cat_filter
structure at level level in the filter stack of session. The copy is written to the filter pointed to by filter.
Level 0 is the topmost filter and the level increases for the lower filters.
Returns CAT_ENOTFOUND
when indexing outside the stack (for example, when the bottom is reached)
or CAT_OK
otherwise.
The I/O Handler is never returned by this function.