curl_multi_fdset(3) libcurl Manual curl_multi_fdset(3)NAMEcurl_multi_fdset - extracts file descriptor information from
a multi handle
SYNOPSIS
#include <curl/curl.h>
CURLMcode curl_multi_fdset(CURLM *multi_handle,
fd_set *read_fd_set,
fd_set *write_fd_set,
fd_set *exc_fd_set,
int *max_fd);
DESCRIPTION
This function extracts file descriptor information from a
given multi_handle. libcurl returns its fd_set sets. The
application can use these to select() on, but be sure to
FD_ZERO them before calling this function as
curl_multi_fdset(3) only adds its own descriptors it doesn't
zero or otherwise remove any other. The
curl_multi_perform(3) function should be called as soon as
one of them are ready to be read from or written to.
If no file descriptors are set by libcurl, max_fd will con-
tain -1 when this function returns. Otherwise it will con-
tain the higher descriptor number libcurl set.
You should also be aware that when doing select(), you
should consider using a rather small (single-digit number of
seconds) timeout and call curl_multi_perform regularly -
even if no activity has been seen on the fd_sets - as other-
wise libcurl-internal retries and timeouts may not work as
you'd think and want.
RETURN VALUE
CURLMcode type, general libcurl multi interface error code.
See libcurl-errors(3)SEE ALSOcurl_multi_cleanup(3),curl_multi_init(3)libcurl 7.9.5 Last change: 25 Apr 2005 1
