ares_reinit(3)

ares_reinit3

Reinitialize a resolver channel from system configuration.

Usage

#include <ares.h>
int ares_reinit(ares_channel_t *channel)

Overview

The ares_reinit(3) function re-reads the system configuration and safely applies the configuration to the existing channel. System configuration will never override user-provided settings such as provided via ares_init_options(3) or ares_set_servers(3).

Any existing queries will be automatically requeued if the server they are currently assigned to is removed from the system configuration.

This function may cause additional file descriptors to be created, and existing ones to be destroyed if server configuration has changed.

d safety, will spawn a background thread to read the configuration and apply it. It is crucial that developers use the ARES_OPT_SOCK_STATE_CB or ARES_OPT_EVENT_THREAD so that notifications of changes are alerted. If using ares_getsock(3) or ares_fds(3), no notification is possible which could cause a stall.

Return values

ares_reinit(3) can return any of the following values:

ARES_SUCCESS

Initialization succeeded.

ARES_EFILE

A configuration file could not be read.

ARES_ENOMEM

The process's available memory was exhausted.

Releases

Unchanged in 2 releases since Debian 13 (Trixie).

  1. 13–Arch

Availability

This function was first introduced in c-ares version 1.22.0.

From c-ares 1.34.9-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.