.\" .\" Copyright 1998 by the Massachusetts Institute of Technology. .\" Copyright (C) 2008-2010 by Daniel Stenberg .\" .\" Permission to use, copy, modify, and distribute this .\" software and its documentation for any purpose and without .\" fee is hereby granted, provided that the above copyright .\" notice appear in all copies and that both that copyright .\" notice and this permission notice appear in supporting .\" documentation, and that the name of M.I.T. not be used in .\" advertising or publicity pertaining to distribution of the .\" software without specific, written prior permission. .\" M.I.T. makes no representations about the suitability of .\" this software for any purpose. It is provided "as is" .\" without express or implied warranty. .\" .\" SPDX-License-Identifier: MIT .\" .TH ARES_GET_SERVERS 3 "5 March 2010" .SH NAME ares_get_servers, ares_get_servers_ports \- Retrieve name servers from an initialized ares_channel (deprecated) .SH SYNOPSIS .nf #include int ares_get_servers(ares_channel_t *\fIchannel\fP, struct ares_addr_node **\fIservers\fP) int ares_get_servers_ports(ares_channel_t *\fIchannel\fP, struct ares_addr_port_node **\fIservers\fP) .fi .SH DESCRIPTION The \fBares_get_servers(3)\fP function retrieves name servers configuration from the channel data identified by .IR channel , as a linked list of ares_addr_node structs storing a pointer to the first node at the address specified by .IR servers . The \fBares_get_servers_ports(3)\fP function also retrieves any per-server port information that may have been previously configured, returning a linked list of ares_addr_port structures. Function caller may traverse the returned name server linked list, or may use it directly as suitable input for the \fBares_set_servers(3)\fP / \fBares_set_servers_ports(3)\fP functions, but shall not shrink or extend the list on its own. Each node of the name server linked list is stored in memory dynamically allocated and managed by c-ares. It is the caller's responsibility to free the resulting linked list, using \fBares_free_data(3)\fP , once the caller does not need it any longer. This function is capable of handling IPv4 and IPv6 name server addresses simultaneously, rendering \fBares_save_options(3)\fP with optmask \fBARES_OPT_SERVERS\fP functionally obsolete except for IPv4-only name server usage. .SH RETURN VALUES This function may return any of the following values: .TP 15 .B ARES_SUCCESS The name servers configuration was successfully retrieved .TP 15 .B ARES_ENOMEM The memory was exhausted .TP 15 .B ARES_ENODATA The channel data identified by .IR channel was invalid. .SH SEE ALSO .BR ares_set_servers (3), .BR ares_init_options (3), .BR ares_save_options(3) .SH AVAILABILITY \fBares_get_servers(3)\fP was added in c-ares 1.7.1; \fBares_get_servers_ports(3)\fP was added in c-ares 1.11.0. .SH NOTES As of c-ares 1.24, these functions are deprecated due to their lack of ability to store the entire server configuration. Use \fBares_get_servers_csv(3)\fP. .SH AUTHOR Implementation of this function and associated library internals are based on code, comments and feedback provided in November and December of 2008 by Daniel Stenberg, Gregor Jasny, Phil Blundell and Yang Tse, December 2009 by Cedric Bail, February 2010 by Jakub Hrozek. On March 2010 Yang Tse shuffled all the bits and this function popped out. .br Copyright 1998 by the Massachusetts Institute of Technology. .br Copyright (C) 2008-2010 by Daniel Stenberg