2003-10-07 17:54:04 -04:00
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.\" $Id$
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.\"
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.\" Copyright 1998 by the Massachusetts Institute of Technology.
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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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.TH ARES_PROCESS 3 "25 July 1998"
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.SH NAME
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ares_process \- Process events for name resolution
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.SH SYNOPSIS
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.nf
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.B #include <ares.h>
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.PP
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.B void ares_process(ares_channel \fIchannel\fP, fd_set *\fIread_fds\fP,
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.B fd_set *\fIwrite_fds\fP)
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.fi
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.SH DESCRIPTION
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The
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.B ares_process
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function handles input/output events and timeouts associated with
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queries pending on the name service channel identified by
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.IR channel .
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The file descriptor sets pointed to by
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.I read_fds
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and
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.I write_fds
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should have file descriptors set in them according to whether the file
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2004-04-02 04:50:42 -05:00
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descriptors specified by \fIares_fds(3)\fP are ready for reading and writing.
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(The easiest way to determine this information is to invoke
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.B select
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with a timeout no greater than the timeout given by \fIares_timeout(3)\fP ).
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.PP
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The
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.B ares_process
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function will invoke callbacks for pending queries if they complete
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successfully or fail.
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.SS EXAMPLE
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The following code fragment waits for all pending queries on a channel
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to complete:
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.PP
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.RS
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.nf
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int nfds, count;
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fd_set readers, writers;
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struct timeval tv, *tvp;
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while (1)
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{
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FD_ZERO(&readers);
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FD_ZERO(&writers);
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nfds = ares_fds(channel, &readers, &writers);
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if (nfds == 0)
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break;
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tvp = ares_timeout(channel, NULL, &tv);
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count = select(nfds, &readers, &writers, NULL, tvp);
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ares_process(channel, &readers, &writers);
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}
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.fi
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.RE
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.SH SEE ALSO
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.BR ares_fds (3),
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.BR ares_timeout (3)
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.SH AUTHOR
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Greg Hudson, MIT Information Systems
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.br
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Copyright 1998 by the Massachusetts Institute of Technology.
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