.\"
.\" Copyright 1998 by the Massachusetts Institute of Technology.
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.\" SPDX-License-Identifier: MIT
.\"
.TH ARES_FDS 3 "23 July 1998"
.SH NAME
ares_fds \- return file descriptors to select on
.SH SYNOPSIS
.nf
#include <ares.h>

int ares_fds(ares_channel_t *\fIchannel\fP,
             fd_set *\fIread_fds\fP,
	     fd_set *\fIwrite_fds\fP)
.fi
.SH DESCRIPTION
The \fBares_fds(3)\fP function retrieves the set of file descriptors which the
calling application should select on for reading and writing for the
processing of name service queries pending on the name service channel
identified by \fIchannel\fP.

File descriptors will be set in the file descriptor sets pointed to by
\fIread_fds\fP and \fIwrite_fds\fP as appropriate.  File descriptors already
set in \fIread_fds\fP and \fIwrite_fds\fP will remain set; initialization of
the file descriptor sets (using \fBFD_ZERO\fP) is the responsibility of the
caller.
.SH RETURN VALUES
\fBares_fds(3)\fP returns a value that is one greater than the number of the
highest socket set in either \fIread_fds\fP or \fIwrite_fds\fP.  If no queries
are active, \fBares_fds(3)\fP returns 0.
.SH SEE ALSO
.BR ares_timeout (3),
.BR ares_process (3)
.SH AUTHOR
Greg Hudson, MIT Information Systems
.br
Copyright 1998 by the Massachusetts Institute of Technology.