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