1ARES_PROCESS(3)            Library Functions Manual            ARES_PROCESS(3)
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NAME

6       ares_process - Process events for name resolution
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SYNOPSIS

9       #include <ares.h>
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11       void ares_process(ares_channel channel, fd_set *read_fds,
12       fd_set *write_fds)
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14       void   ares_process_fd(ares_channel   channel,  ares_socket_t  read_fd,
15       ares_socket_t write_fd)
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DESCRIPTION

18       The ares_process(3) function handles input/output events  and  timeouts
19       associated  with queries pending on the name service channel identified
20       by channel.  The file  descriptor  sets  pointed  to  by  read_fds  and
21       write_fds should have file descriptors set in them according to whether
22       the file descriptors specified by ares_fds(3) are ready for reading and
23       writing.   (The  easiest way to determine this information is to invoke
24       select with a timeout no greater than the timeout given  by  ares_time‐
25       out(3) ).
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27       The  ares_process function will invoke callbacks for pending queries if
28       they complete successfully or fail.
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30       ares_process_fd(3) works the same way but acts and operates only on the
31       specific  file  descriptors  (sockets) you pass in to the function. Use
32       ARES_SOCKET_BAD for "no action". This function is of course provided to
33       allow users of c-ares to void select() in their applications and within
34       c-ares.
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36   EXAMPLE
37       The following code fragment waits for all pending queries on a  channel
38       to complete:
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40              int nfds, count;
41              fd_set readers, writers;
42              struct timeval tv, *tvp;
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44              while (1)
45                {
46                  FD_ZERO(&readers);
47                  FD_ZERO(&writers);
48                  nfds = ares_fds(channel, &readers, &writers);
49                  if (nfds == 0)
50                    break;
51                  tvp = ares_timeout(channel, NULL, &tv);
52                  count = select(nfds, &readers, &writers, NULL, tvp);
53                  ares_process(channel, &readers, &writers);
54                }
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SEE ALSO

57       ares_fds(3), ares_timeout(3)
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AUTHOR

60       Greg Hudson, MIT Information Systems
61       Copyright 1998 by the Massachusetts Institute of Technology.
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65                                 25 July 1998                  ARES_PROCESS(3)