NAME¶
curl_multi_info_read - read multi stack informationals
SYNOPSIS¶
#include <curl/curl.h>
CURLMsg *curl_multi_info_read( CURLM *multi_handle,
int *msgs_in_queue);
DESCRIPTION¶
Ask the multi handle if there are any messages/informationals from the
individual transfers. Messages may include informationals such as an error
code from the transfer or just the fact that a transfer is completed. More
details on these should be written down as well.
Repeated calls to this function will return a new struct each time, until a NULL
is returned as a signal that there is no more to get at this point. The
integer pointed to with
msgs_in_queue will contain the number of
remaining messages after this function was called.
When you fetch a message using this function, it is removed from the internal
queue so calling this function again will not return the same message again.
It will instead return new messages at each new invoke until the queue is
emptied.
WARNING: The data the returned pointer points to will not survive calling
curl_multi_cleanup(3),
curl_multi_remove_handle(3) or
curl_easy_cleanup(3).
The 'CURLMsg' struct is very simple and only contains very basic information. If
more involved information is wanted, the particular "easy handle" in
present in that struct and can thus be used in subsequent regular
curl_easy_getinfo(3) calls (or similar):
struct CURLMsg {
CURLMSG msg; /* what this message means */
CURL *easy_handle; /* the handle it concerns */
union {
void *whatever; /* message-specific data */
CURLcode result; /* return code for transfer */
} data;
};
When
msg is
CURLMSG_DONE, the message identifies a transfer that
is done, and then
result contains the return code for the easy handle
that just completed.
At this point, there are no other
msg types defined.
RETURN VALUE¶
A pointer to a filled-in struct, or NULL if it failed or ran out of structs. It
also writes the number of messages left in the queue (after this read) in the
integer the second argument points to.
SEE ALSO¶
curl_multi_cleanup(3),
curl_multi_init(3),
curl_multi_perform(3)