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Diffstat (limited to 'docs/libcurl/opts/GNURLMOPT_SOCKETFUNCTION.3')
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1 files changed, 110 insertions, 0 deletions
diff --git a/docs/libcurl/opts/GNURLMOPT_SOCKETFUNCTION.3 b/docs/libcurl/opts/GNURLMOPT_SOCKETFUNCTION.3 new file mode 100644 index 000000000..cd7b49dce --- /dev/null +++ b/docs/libcurl/opts/GNURLMOPT_SOCKETFUNCTION.3 @@ -0,0 +1,110 @@ +.\" ************************************************************************** +.\" * _ _ ____ _ +.\" * 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.haxx.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 GNURLMOPT_SOCKETFUNCTION 3 "3 Nov 2016" "libcurl 7.39.0" "curl_multi_setopt options" +.SH NAME +CURLMOPT_SOCKETFUNCTION \- callback informed about what to wait for +.SH SYNOPSIS +.nf +#include <gnurl/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) " |