PCAP_SET_TSTAMP_PRECISION(3)

📦 version 15.1, in freebsd 14.5, freebsd 15.1

🌸 NAME 🌸

pcap_set_tstamp_precision — set the time stamp precision returned in captures. That’s the whole assignment, bestie: you’re telling libpcap what time-stamp precision you want for captured packets, no cap.

This page lives in the Library Functions Manual, and it’s giving very specific “configure your capture handle before you activate it” energy. 💅

✨ SYNOPSIS ✨

#include <pcap/pcap.h>

int pcap_set_tstamp_precision(pcap_t *p, int tstamp_precision);

🦋 DESCRIPTION 🦋

Okay so pcap_set_tstamp_precision() sets the precision of the time stamp desired for packets captured on the pcap descriptor to the type specified by tstamp_precision.

The way that this works is: it must be called on a pcap descriptor created by pcap_create(3) that has not yet been activated by pcap_activate(3). Like, do not try to sneak this in after activation — that’s not the vibe. 🙈

Two time stamp precisions are supported, bestie:

  • microseconds
  • nanoseconds

You can use these options to request the precision you want:

  • PCAP_TSTAMP_PRECISION_MICRO
  • PCAP_TSTAMP_PRECISION_NANO

By default, time stamps are in microseconds. Periodt. ⭐

💖 RETURN VALUE 💖

pcap_set_tstamp_precision() returns 0 on success if the specified time stamp precision is expected to be supported by the capture device. Slay. ✨

It can also return:

  • PCAP_ERROR_TSTAMP_PRECISION_NOTSUP — if the capture device does not support the requested time stamp precision.
  • PCAP_ERROR_ACTIVATED — if called on a capture handle that has been activated.
Like, read the room: if the handle is already activated, PCAP_ERROR_ACTIVATED is the energy you get. 💀

🎀 BACKWARD COMPATIBILITY 🎀

This function became available in libpcap release 1.5.1.

In previous releases, time stamps from a capture device or savefile are always given in seconds and microseconds. So if you’re time-traveling through old libpcap versions, that’s the situation. 🕰️

🌈 SEE ALSO 🌈

Mwah 💋 — signing off from the Library Functions Manual, page PCAP_SET_T...P_PRECISION(3), dated 23 August 2018. Stay precise, bestie. 🫶✨

📦 where this page comes from