---
name: "pcap_set_tstamp_type"
section: "3"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd"]
url: "https://new.carta.tech/pcap_set_tstamp_type"
---

# pcap\_set\_tstamp\_type(3)

set the time stamp type to be used by a capture device

## NAME

pcap\_set\_tstamp\_type - set the time stamp type to be used by a capture device

## SYNOPSIS

```
#include <pcap/pcap.h>
```

**int pcap\_set\_tstamp\_type(pcap\_t \*p, int tstamp\_type);**

## DESCRIPTION

**pcap\_set\_tstamp\_type**() sets the type of time stamp desired for packets captured on the pcap descriptor to the type specified by *tstamp\_type*. It must be called on a pcap descriptor created by [**pcap\_create**(3)](/pcap_create/3.md) that has not yet been activated by [**pcap\_activate**(3)](/pcap_activate/3.md). [**pcap\_list\_tstamp\_types**(3)](/pcap_list_tstamp_types/3.md) will give a list of the time stamp types supported by a given capture device. See [**pcap-tstamp**(7)](/pcap-tstamp/7.md) for a list of all the time stamp types.

## RETURN VALUE

**pcap\_set\_tstamp\_type**() returns **0** on success if the specified time stamp type is expected to be supported by the capture device, **PCAP\_WARNING\_TSTAMP\_TYPE\_NOTSUP** if the specified time stamp type is not supported by the capture device, **PCAP\_ERROR\_ACTIVATED** if called on a capture handle that has been activated, and **PCAP\_ERROR\_CANTSET\_TSTAMP\_TYPE** if the capture device doesn't support setting the time stamp type (only older versions of libpcap will return that; newer versions will always allow the time stamp type to be set to the default type).

## BACKWARD COMPATIBILITY

This function became available in libpcap release 1.2.1.  In previous releases, the time stamp type cannot be set; only the default time stamp type offered by a capture source is available.

## SEE ALSO

[**pcap**(3)](/pcap/3.md), [**pcap\_tstamp\_type\_name\_to\_val**(3)](/pcap_tstamp_type_name_to_val/3.md)