pcap_is_swapped - find out whether a savefile has the native byte order
#include <pcap/pcap.h>
int pcap_is_swapped(pcap_t *p);
pcap_is_swapped() returns true (1) if p refers to a ``savefile''
  that uses a different byte order than the current system. For a live capture,
  it always returns false (0).
It must not be called on a pcap descriptor created by
    pcap_create(3) that has not yet been activated by
    pcap_activate(3).
pcap_is_swapped() returns true (1) or false (0) on success and
  PCAP_ERROR_NOT_ACTIVATED if called on a capture handle that has been
  created but not activated.