ares_fds(3) [debian man page]

ARES_FDS(3)						     Library Functions Manual						       ARES_FDS(3)

NAME

       ares_fds - Get file descriptors to select on for name service

SYNOPSIS

       #include <ares.h>

       int ares_fds(ares_channel channel, fd_set *read_fds,
       fd_set *write_fds)

DESCRIPTION

       The  ares_fds 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 channel.  File descriptors will be	set  in  the  file
       descriptor  sets  pointed  to by read_fds and write_fds as appropriate.	File descriptors already set in read_fds and write_fds will remain
       set; initialization of the file descriptor sets (using FD_ZERO) is the responsibility of the caller.

RETURN VALUES

       ares_fds returns one greater than the number of the highest socket set in either read_fds or write_fds.	If no queries are active, ares_fds
       will return 0.

SEE ALSO

       ares_timeout(3), ares_process(3)

AUTHOR

       Greg Hudson, MIT Information Systems
       Copyright 1998 by the Massachusetts Institute of Technology.

								   23 July 1998 						       ARES_FDS(3)

ARES_PROCESS(3) 					     Library Functions Manual						   ARES_PROCESS(3)

NAME

       ares_process - Process events for name resolution

SYNOPSIS

       #include <ares.h>

       void ares_process(ares_channel channel, fd_set *read_fds,
       fd_set *write_fds)

       void ares_process_fd(ares_channel channel, ares_socket_t read_fd, ares_socket_t write_fd)

DESCRIPTION

       The  ares_process(3)  function handles input/output events and timeouts associated with queries pending on the name service channel identi-
       fied by channel.  The file descriptor sets pointed to by read_fds and write_fds should have file  descriptors  set  in  them  according	to
       whether the file descriptors specified by ares_fds(3) are ready for reading and writing.  (The easiest way to determine this information is
       to invoke select with a timeout no greater than the timeout given by ares_timeout(3) ).

       The ares_process function will invoke callbacks for pending queries if they complete successfully or fail.

       ares_process_fd(3) works the same way but acts and operates only on the specific file descriptors (sockets) you pass in	to  the  function.
       Use  ARES_SOCKET_BAD  for  "no action". This function is of course provided to allow users of c-ares to void select() in their applications
       and within c-ares.

   EXAMPLE
       The following code fragment waits for all pending queries on a channel to complete:

	      int nfds, count;
	      fd_set readers, writers;
	      struct timeval tv, *tvp;

	      while (1)
		{
		  FD_ZERO(&readers);
		  FD_ZERO(&writers);
		  nfds = ares_fds(channel, &readers, &writers);
		  if (nfds == 0)
		    break;
		  tvp = ares_timeout(channel, NULL, &tv);
		  count = select(nfds, &readers, &writers, NULL, tvp);
		  ares_process(channel, &readers, &writers);
		}

SEE ALSO

       ares_fds(3), ares_timeout(3)

AUTHOR

       Greg Hudson, MIT Information Systems
       Copyright 1998 by the Massachusetts Institute of Technology.

								   25 July 1998 						   ARES_PROCESS(3)