1curl_multi_info_read(3) libcurl Manual curl_multi_info_read(3)
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6 curl_multi_info_read - read multi stack informationals
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9 #include <curl/curl.h>
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11 CURLMsg *curl_multi_info_read( CURLM *multi_handle,
12 int *msgs_in_queue);
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15 Ask the multi handle if there are any messages/informationals from the
16 individual transfers. Messages may include informationals such as an
17 error code from the transfer or just the fact that a transfer is com‐
18 pleted. More details on these should be written down as well.
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20 Repeated calls to this function will return a new struct each time,
21 until a NULL is returned as a signal that there is no more to get at
22 this point. The integer pointed to with msgs_in_queue will contain the
23 number of remaining messages after this function was called.
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25 When you fetch a message using this function, it is removed from the
26 internal queue so calling this function again will not return the same
27 message again. It will instead return new messages at each new invoke
28 until the queue is emptied.
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30 WARNING: The data the returned pointer points to will not survive call‐
31 ing curl_multi_cleanup(3), curl_multi_remove_handle(3) or
32 curl_easy_cleanup(3).
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34 The 'CURLMsg' struct is very simple and only contains very basic infor‐
35 mation. If more involved information is wanted, the particular "easy
36 handle" in present in that struct and can thus be used in subsequent
37 regular curl_easy_getinfo(3) calls (or similar):
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39 struct CURLMsg {
40 CURLMSG msg; /* what this message means */
41 CURL *easy_handle; /* the handle it concerns */
42 union {
43 void *whatever; /* message-specific data */
44 CURLcode result; /* return code for transfer */
45 } data;
46 };
47 When msg is CURLMSG_DONE, the message identifies a transfer that is
48 done, and then result contains the return code for the easy handle that
49 just completed.
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51 At this point, there are no other msg types defined.
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54 A pointer to a filled-in struct, or NULL if it failed or ran out of
55 structs. It also writes the number of messages left in the queue (after
56 this read) in the integer the second argument points to.
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59 curl_multi_cleanup(3), curl_multi_init(3), curl_multi_perform(3)
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63libcurl 7.10.3 18 Dec 2004 curl_multi_info_read(3)