Blame view

3rdparty/curl/share/man/man3/CURLMOPT_SOCKETFUNCTION.3 3.9 KB
a86c63ca   Hu Chunming   提交三方库文件
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
  .\" **************************************************************************
  .\" *                                  _   _ ____  _
  .\" *  Project                     ___| | | |  _ \| |
  .\" *                             / __| | | | |_) | |
  .\" *                            | (__| |_| |  _ <| |___
  .\" *                             \___|\___/|_| \_\_____|
  .\" *
  .\" * Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al.
  .\" *
  .\" * This software is licensed as described in the file COPYING, which
  .\" * you should have received as part of this distribution. The terms
  .\" * are also available at https://curl.se/docs/copyright.html.
  .\" *
  .\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
  .\" * copies of the Software, and permit persons to whom the Software is
  .\" * furnished to do so, under the terms of the COPYING file.
  .\" *
  .\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  .\" * KIND, either express or implied.
  .\" *
  .\" **************************************************************************
  .\"
  .TH CURLMOPT_SOCKETFUNCTION 3 "November 04, 2020" "libcurl 7.77.0" "curl_multi_setopt options"
  
  .SH NAME
  CURLMOPT_SOCKETFUNCTION \- callback informed about what to wait for
  .SH SYNOPSIS
  .nf
  #include <curl/curl.h>
  
  int socket_callback(CURL *easy,      /* easy handle */
                      curl_socket_t s, /* socket */
                      int what,        /* describes the socket */
                      void *userp,     /* private callback pointer */
                      void *socketp);  /* private socket pointer */
  
  CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_SOCKETFUNCTION, socket_callback);
  .SH DESCRIPTION
  Pass a pointer to your callback function, which should match the prototype
  shown above.
  
  When the \fIcurl_multi_socket_action(3)\fP function is called, it informs the
  application about updates in the socket (file descriptor) status by doing
  none, one, or multiple calls to the \fBsocket_callback\fP. The callback
  function gets status updates with changes since the previous time the callback
  was called. If the given callback pointer is set to NULL, no callback will be
  called.
  .SH "CALLBACK ARGUMENTS"
  \fIeasy\fP identifies the specific transfer for which this update is related.
  
  \fIs\fP is the specific socket this function invocation concerns. If the
  \fBwhat\fP argument is not CURL_POLL_REMOVE then it holds information about
  what activity on this socket the application is supposed to
  monitor. Subsequent calls to this callback might update the \fBwhat\fP bits
  for a socket that is already monitored.
  
  \fBuserp\fP is set with \fICURLMOPT_SOCKETDATA(3)\fP.
  
  \fBsocketp\fP is set with \fIcurl_multi_assign(3)\fP or will be NULL.
  
  The \fBwhat\fP parameter informs the callback on the status of the given
  socket. It can hold one of these values:
  .IP CURL_POLL_IN
  Wait for incoming data. For the socket to become readable.
  .IP CURL_POLL_OUT
  Wait for outgoing data. For the socket to become writable.
  .IP CURL_POLL_INOUT
  Wait for incoming and outgoing data. For the socket to become readable or
  writable.
  .IP CURL_POLL_REMOVE
  The specified socket/file descriptor is no longer used by libcurl.
  .SH DEFAULT
  NULL (no callback)
  .SH PROTOCOLS
  All
  .SH EXAMPLE
  .nf
  static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
  {
    GlobalInfo *g = (GlobalInfo*) cbp;
    SockInfo *fdp = (SockInfo*) sockp;
  
    if(what == CURL_POLL_REMOVE) {
      remsock(fdp);
    }
    else {
      if(!fdp) {
        addsock(s, e, what, g);
      }
      else {
        setsock(fdp, s, e, what, g);
      }
    }
    return 0;
  }
  
  main()
  {
    GlobalInfo setup;
    /* ... use socket callback and custom pointer */
    curl_multi_setopt(multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
    curl_multi_setopt(multi, CURLMOPT_SOCKETDATA, &setup);
  }
  .fi
  .SH AVAILABILITY
  Added in 7.15.4
  .SH RETURN VALUE
  Returns CURLM_OK.
  .SH "SEE ALSO"
  .BR CURLMOPT_SOCKETDATA "(3), " curl_multi_socket_action "(3), "
  .BR CURLMOPT_TIMERFUNCTION "(3) "