---
name: "dnsjit.input.pcap"
section: "3"
platform: "linux"
package: "dnsjit"
version: "1.5.0-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/dnsjit.input.pcap"
---

# dnsjit.input.pcap(3)

Read input from an interface or PCAP file using libpcap

## NAME

dnsjit.input.pcap - Read input from an interface or PCAP file using libpcap

## SYNOPSIS

  local input = require("dnsjit.input.pcap").new()\
   input:open\_offline("file.pcap")\
   input:receiver(filter\_or\_output)\
   input:run()

## DESCRIPTION

Input module for reading packets from interfaces and PCAP files.

### Functions

- **Pcap.new**()

  Create a new Pcap input.

- **Pcap:log**()

  Return the Log object to control logging of this instance or module.

- **Pcap:receiver**(o)

  Set the receiver to pass objects to.

- **Pcap:produce**()

  Return the C functions and context for producing objects.

- **Pcap:create**(source)

  Open a live packet capture on *source*, which is an interface name or "any" (Linux) / "all" (BSD). Must be activated before use.

- **Pcap:activate**()

  Activate a live packet capture, see [**pcap\_activate**(3pcap)](/pcap_activate/3pcap.md) for more information and possible return values.

- **Pcap:open\_offline**(file)

  Open a PCAP file for processing, see [**pcap\_open\_offline**(3pcap)](/pcap_open_offline/3pcap.md) for more information. Returns 0 on success.

- **Pcap:loop**(cnt)

  Process packets from a live capture or savefile until *cnt* packets are processed, see [**pcap\_loop**(3pcap)](/pcap_loop/3pcap.md) for more information and possible return values.

- **Pcap:dispatch**(cnt)

  Process packets from a live capture or savefile until *cnt* packets are processed, see [**pcap\_dispatch**(3pcap)](/pcap_dispatch/3pcap.md) for more information and possible return values.

- **Pcap:packets**()

  Return the number of packets seen.

- **Pcap:linktype**()

  Return the linktype of the opened PCAP.

- **Pcap:snaplen**()

  Return the snaplen of the opened PCAP.

## SEE ALSO

[**dnsjit.output.pcap**(3)](/dnsjit.output.pcap/3.md)

## AUTHORS and CONTRIBUTORS

Jerry Lundström (DNS-OARC), Tomáš Křížek (CZ.NIC), Petr Špaček (ISC)

Maintained by DNS-OARC

*https://www.dns-oarc.net/*

## BUGS

For issues and feature requests please use:

*https://github.com/DNS-OARC/dnsjit/issues*

For question and help please use:

*admin@dns-oarc.net*