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.\" Copyright 1998 by the Massachusetts Institute of Technology.
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.TH ARES_PROCESS 3 "25 July 1998"
ares_process \- Process events for name resolution
.B #include <ares.h>
.B void ares_process(ares_channel \fIchannel\fP, fd_set *\fIread_fds\fP,
.B fd_set *\fIwrite_fds\fP)
.B void ares_process_fd(ares_channel \fIchannel\fP,
.B ares_socket_t \fIread_fd\fP,
.B ares_socket_t \fIwrite_fd\fP)
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 ).
.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.
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)
nfds = ares_fds(channel, &readers, &writers);
if (nfds == 0)
tvp = ares_timeout(channel, NULL, &tv);
count = select(nfds, &readers, &writers, NULL, tvp);
ares_process(channel, &readers, &writers);
.BR ares_fds (3),
.BR ares_timeout (3)
Greg Hudson, MIT Information Systems
Copyright 1998 by the Massachusetts Institute of Technology.