pcap_list_datalinks(3)

pcap_list_datalinks3

Get a list of link-layer header types supported by a capture device, and free that list

Usage

#include <pcap/pcap.h>

int pcap_list_datalinks(pcap_t *p, int **dlt_buf); void pcap_free_datalinks(int *dlt_list);

Overview

pcap_list_datalinks() is used to get a list of the supported link-layer header types of the interface associated with the pcap descriptor. pcap_list_datalinks() allocates an array to hold the list and sets *dlt_buf to point to that array.

The caller is responsible for freeing the array with pcap_free_datalinks(), which frees the list of link-layer header types pointed to by dlt_list.

It must not be called on a pcap descriptor created by pcap_create(3) that has not yet been activated by pcap_activate(3).

Return value

pcap_list_datalinks() returns the number of link-layer header types in the array on success, PCAP_ERROR_NOT_ACTIVATED if called on a capture handle that has been created but not activated, and PCAP_ERROR on other errors. If PCAP_ERROR is returned, pcap_geterr(3) or pcap_perror(3) may be called with p as an argument to fetch or display the error text.

Releases

39 releases since FreeBSD 8.0-RELEASE; the text changed 7 times.

  1. 8.0–9.0
  2. 9.1–10.4
  3. 11.0–11.2
  4. 11.3
  5. 11.4
  6. 12.0–12.1
  7. 12.2–13.4
  8. 13.5–16.0

From base 16.0-CURRENT-20261027-61c70dc16a79 in FreeBSD 16.0-CURRENT (2026-10-27). Parsed by carta from the page's man source.