#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);
|multi_handle||Pointer to a multi handle.|
|read_fd_set||Pointer to a read file descriptor set.|
|write_fd_set||Pointer to a write file descriptor set.|
|exc_fd_set||Pointer to an exc fd set.|
|max_fd||Pointer to the maximum number of file descriptors.|
If the operation was successful,
CURLM_OK is returned. Otherwise, a specific
CURLM libcurl Error Code is returned.
This function extracts file descriptor information from a given multi_handle. libcurl returns its
The application can use these to select on, but be sure to
FD_ZERO them before calling this function as
curl_multi_fdset only adds its own descriptors, it does not
zero or otherwise remove any others. The
curl_multi_perform function should be called as soon as one of them is ready to be read from or
To ensure up-to-date results, call
curl_multi_perform until it does not return
CURLM_CALL_MULTI_PERFORM prior to
curl_multi_fdset. This will ensure that libcurl has updated the handles' socket states.
If no file descriptors are set by libcurl, max_fd will contain
-1 when this function returns. Otherwise it will contain the higher descriptor
number libcurl set.
When doing select, use
curl_multi_timeout to determine how long to wait for action.
curl_multi_perform even if no activity has been seen on the
fd_sets after the timeout expires.
Otherwise, internal retries and timeouts may not work as expected.
2013/05/08 Automated cleanup pass.
2012/05/04 Initial version.