1curl_multi_socket(3)            libcurl Manual            curl_multi_socket(3)
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NAME

6       curl_multi_socket - reads/writes available data
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SYNOPSIS

9       #include <curl/curl.h>
10       CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t sockfd,
11                                   int *running_handles);
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13       CURLMcode curl_multi_socket_all(CURLM *multi_handle,
14                                       int *running_handles);
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DESCRIPTION

17       These  functions  are deprecated. Do not use. See curl_multi_socket_ac‐
18       tion(3) instead.
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20       At return, the integer running_handles points to will contain the  num‐
21       ber  of  still  running easy handles within the multi handle. When this
22       number reaches zero, all transfers are complete/done.  Note  that  when
23       you  call  curl_multi_socket_action(3)  on  a  specific  socket and the
24       counter decreases by one, it DOES NOT necessarily mean that this  exact
25       socket/transfer  is the one that completed. Use curl_multi_info_read(3)
26       to figure out which easy handle that completed.
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28       The curl_multi_socket_action(3) functions inform the application  about
29       updates  in  the socket (file descriptor) status by doing none, one, or
30       multiple calls to the socket  callback  function  set  with  the  CURL‐
31       MOPT_SOCKETFUNCTION(3)  option to curl_multi_setopt(3). They update the
32       status with changes since the previous time the callback was called.
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34       Get the timeout time by setting  the  CURLMOPT_TIMERFUNCTION(3)  option
35       with  curl_multi_setopt(3).  Your application will then get called with
36       information on how long to wait for socket actions at most before doing
37       the  timeout action: call the curl_multi_socket_action(3) function with
38       the sockfd argument set to CURL_SOCKET_TIMEOUT. You can  also  use  the
39       curl_multi_timeout(3) function to poll the value at any given time, but
40       for an event-based system using the callback is far better than relying
41       on polling the timeout value.
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43       Usage  of  curl_multi_socket(3)  is deprecated, whereas the function is
44       equivalent to curl_multi_socket_action(3) with ev_bitmask set to 0.
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46       Force libcurl to (re-)check all its internal sockets and transfers  in‐
47       stead  of  just  a single one by calling curl_multi_socket_all(3). Note
48       that there should not be any reason to use this function.
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EXAMPLE

51       /* the event-library gets told when there activity on the socket 'fd',
52          which we translate to a call to curl_multi_socket_action() */
53       int running;
54       rc = curl_multi_socket(multi_handle, fd, &running);
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AVAILABILITY

57       This function was added in libcurl 7.15.4, and is deemed  stable  since
58       7.16.0.
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60       curl_multi_socket(3) is deprecated, use curl_multi_socket_action(3) in‐
61       stead!
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RETURN VALUE

64       CURLMcode type, general libcurl multi interface error code.
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66       The return code is for the whole multi stack. Problems still might have
67       occurred  on  individual transfers even when one of these functions re‐
68       turn OK.
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SEE ALSO

71       curl_multi_cleanup(3),     curl_multi_init(3),     curl_multi_fdset(3),
72       curl_multi_info_read(3), the hiperfifo.c example
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76libcurl 7.82.0                 January 11, 2022           curl_multi_socket(3)