---
name: "sysdecode_kevent"
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/sysdecode_kevent"
---

# sysdecode\_kevent(3)

output description of kevent structure fields

## NAME

**sysdecode\_kevent**, **sysdecode\_kevent\_fflags**, **sysdecode\_kevent\_filter**, **sysdecode\_kevent\_flags** – output description of kevent structure fields

## LIBRARY

library “libsysdecode”

## SYNOPSIS

**#include \<sysdecode.h\>**

*void*\

**sysdecode\_kevent\_fflags**(*FILE \*fp*, *short filter*, *int fflags*, *int base*);

*bool*\

**sysdecode\_kevent\_flags**(*FILE \*fp*, *int flags*, *int \*rem*);

*const* *char* *\**\

**sysdecode\_kevent\_filter**(*int filter*);

## DESCRIPTION

These functions provide text descriptions of *struct* *kevent* fields.

The **sysdecode\_kevent\_fflags**() function outputs a text description of the *fflags* member of a *struct* *kevent* to the stream *fp*. For the EVFILT\_READ, EVFILT\_WRITE, EVFILT\_VNODE, EVFILT\_PROC, EVFILT\_PROCDESC, EVFILT\_TIMER, and EVFILT\_USER filters, **sysdecode\_kevent\_fflags**() outputs a bitmask of filter-specific NOTE\_\* flags as documented in [kevent(2)](/kevent/2.md). For other values of *filter*, the value of *fflags* is output in the indicated *base* (one of 8, 10, or 16).

The **sysdecode\_kevent\_filter**() function returns a text description of the *filter* member of a *struct* *kevent*. NULL is returned if the *filter* value is unknown.

The **sysdecode\_kevent\_flags**() function outputs a text description of the *flags* member of a *struct* *kevent* to the stream *fp*. This function uses the same calling convention and formatting as the other functions described in [sysdecode\_mask(3)](/sysdecode_mask/3.md).

## RETURN VALUES

The **sysdecode\_kevent\_filter** function returns the name of a filter or NULL if the filter value is unknown.

The **sysdecode\_kevent\_flags** function returns true if any flags in the *flags* field were decoded and false if no flags were decoded.

## SEE ALSO

[sysdecode(3)](/sysdecode/3.md), [sysdecode\_enum(3)](/sysdecode_enum/3.md), [sysdecode\_mask(3)](/sysdecode_mask/3.md)