| .\" $Id$ |
| .\" |
| .\" Copyright 1998 by the Massachusetts Institute of Technology. |
| .\" |
| .\" Permission to use, copy, modify, and distribute this |
| .\" software and its documentation for any purpose and without |
| .\" fee is hereby granted, provided that the above copyright |
| .\" notice appear in all copies and that both that copyright |
| .\" notice and this permission notice appear in supporting |
| .\" documentation, and that the name of M.I.T. not be used in |
| .\" advertising or publicity pertaining to distribution of the |
| .\" software without specific, written prior permission. |
| .\" M.I.T. makes no representations about the suitability of |
| .\" this software for any purpose. It is provided "as is" |
| .\" without express or implied warranty. |
| .\" |
| .TH ARES_PROCESS 3 "25 July 1998" |
| .SH NAME |
| ares_process \- Process events for name resolution |
| .SH SYNOPSIS |
| .nf |
| .B #include <ares.h> |
| .PP |
| .B void ares_process(ares_channel \fIchannel\fP, fd_set *\fIread_fds\fP, |
| .B fd_set *\fIwrite_fds\fP) |
| .fi |
| .PP |
| .B void ares_process_fd(ares_channel \fIchannel\fP, |
| .B ares_socket_t \fIread_fd\fP, |
| .B ares_socket_t \fIwrite_fd\fP) |
| .fi |
| .SH DESCRIPTION |
| The \fBares_process(3)\fP function handles input/output events and timeouts |
| associated with queries pending on the name service channel identified by |
| .IR channel . |
| The file descriptor sets pointed to by \fIread_fds\fP and \fIwrite_fds\fP |
| should have file descriptors set in them according to whether the file |
| descriptors specified by \fIares_fds(3)\fP are ready for reading and writing. |
| (The easiest way to determine this information is to invoke |
| .B select |
| with a timeout no greater than the timeout given by \fIares_timeout(3)\fP ). |
| .PP |
| The |
| .B ares_process |
| function will invoke callbacks for pending queries if they complete |
| successfully or fail. |
| |
| \fBares_process_fd(3)\fP 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. |
| .SS EXAMPLE |
| The following code fragment waits for all pending queries on a channel |
| to complete: |
| .PP |
| .RS |
| .nf |
| 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); |
| } |
| .fi |
| .RE |
| .SH SEE ALSO |
| .BR ares_fds (3), |
| .BR ares_timeout (3) |
| .SH AUTHOR |
| Greg Hudson, MIT Information Systems |
| .br |
| Copyright 1998 by the Massachusetts Institute of Technology. |