---
name: "devclass_get_maxunit"
section: "9"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["linux", "freebsd"]
url: "https://new.carta.tech/devclass_get_maxunit"
---

# devclass\_get\_maxunit(9)

find the maximum unit number in the class

## NAME

**devclass\_get\_maxunit** – find the maximum unit number in the class

## SYNOPSIS

**#include \<sys/param.h\>**

**#include \<sys/bus.h\>**

*int*\

**devclass\_get\_maxunit**(*devclass\_t dc*);

## DESCRIPTION

Returns the next unit number to be allocated to device instances in the devclass. This is one greater than the highest currently allocated unit.

## RETURN VALUES

The **devclass\_get\_maxunit**() function returns -1 if *dc* is NULL, otherwise it returns the next unit number in *dc's* devclass.

## ERRORS

None.

## SEE ALSO

[devclass(9)](/devclass/9.md), [device(9)](/device/9.md)

## AUTHORS

This manual page was written by Doug Rabson.

## BUGS

The name is confusing since it is one greater than the maximum unit.