116 lines
4.2 KiB
Groff
116 lines
4.2 KiB
Groff
|
.\" **************************************************************************
|
||
|
|
.\" * _ _ ____ _
|
||
|
|
.\" * Project ___| | | | _ \| |
|
||
|
|
.\" * / __| | | | |_) | |
|
||
|
|
.\" * | (__| |_| | _ <| |___
|
||
|
|
.\" * \___|\___/|_| \_\_____|
|
||
|
|
.\" *
|
||
|
|
.\" * Copyright (C) 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.
|
||
|
|
.\" *
|
||
|
|
.\" * SPDX-License-Identifier: curl
|
||
|
|
.\" *
|
||
|
|
.\" **************************************************************************
|
||
|
|
.\"
|
||
|
|
.TH CURLOPT_XFERINFOFUNCTION 3 "August 22, 2023" "ibcurl 8.3.0" libcurl
|
||
|
|
|
||
|
|
.SH NAME
|
||
|
|
CURLOPT_XFERINFOFUNCTION \- progress meter callback
|
||
|
|
.SH SYNOPSIS
|
||
|
|
.nf
|
||
|
|
#include <curl/curl.h>
|
||
|
|
|
||
|
|
int progress_callback(void *clientp,
|
||
|
|
curl_off_t dltotal,
|
||
|
|
curl_off_t dlnow,
|
||
|
|
curl_off_t ultotal,
|
||
|
|
curl_off_t ulnow);
|
||
|
|
|
||
|
|
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_XFERINFOFUNCTION,
|
||
|
|
progress_callback);
|
||
|
|
.fi
|
||
|
|
.SH DESCRIPTION
|
||
|
|
Pass a pointer to your callback function, which should match the prototype
|
||
|
|
shown above.
|
||
|
|
|
||
|
|
This function gets called by libcurl instead of its internal equivalent with a
|
||
|
|
frequent interval. While data is being transferred it gets called frequently,
|
||
|
|
and during slow periods like when nothing is being transferred it can slow
|
||
|
|
down to about one call per second.
|
||
|
|
|
||
|
|
\fIclientp\fP is the pointer set with \fICURLOPT_XFERINFODATA(3)\fP, it is not
|
||
|
|
used by libcurl but is only passed along from the application to the callback.
|
||
|
|
|
||
|
|
The callback gets told how much data libcurl is about to transfer and has
|
||
|
|
already transferred, in number of bytes. \fIdltotal\fP is the total number of
|
||
|
|
bytes libcurl expects to download in this transfer. \fIdlnow\fP is the number
|
||
|
|
of bytes downloaded so far. \fIultotal\fP is the total number of bytes libcurl
|
||
|
|
expects to upload in this transfer. \fIulnow\fP is the number of bytes
|
||
|
|
uploaded so far.
|
||
|
|
|
||
|
|
Unknown/unused argument values passed to the callback are set to zero (like if
|
||
|
|
you only download data, the upload size remains 0). Many times the callback is
|
||
|
|
called one or more times first, before it knows the data sizes so a program
|
||
|
|
must be made to handle that.
|
||
|
|
|
||
|
|
If your callback function returns CURL_PROGRESSFUNC_CONTINUE it makes libcurl
|
||
|
|
to continue executing the default progress function.
|
||
|
|
|
||
|
|
Returning any other non-zero value from this callback makes libcurl abort the
|
||
|
|
transfer and return \fICURLE_ABORTED_BY_CALLBACK\fP.
|
||
|
|
|
||
|
|
If you transfer data with the multi interface, this function is not called
|
||
|
|
during periods of idleness unless you call the appropriate libcurl function
|
||
|
|
that performs transfers.
|
||
|
|
|
||
|
|
\fICURLOPT_NOPROGRESS(3)\fP must be set to 0 to make this function actually
|
||
|
|
get called.
|
||
|
|
.SH DEFAULT
|
||
|
|
By default, libcurl has an internal progress meter. That is rarely wanted by
|
||
|
|
users.
|
||
|
|
.SH PROTOCOLS
|
||
|
|
All
|
||
|
|
.SH EXAMPLE
|
||
|
|
.nf
|
||
|
|
struct progress {
|
||
|
|
char *private;
|
||
|
|
size_t size;
|
||
|
|
};
|
||
|
|
|
||
|
|
static size_t progress_callback(void *clientp,
|
||
|
|
curl_off_t dltotal,
|
||
|
|
curl_off_t dlnow,
|
||
|
|
curl_off_t ultotal,
|
||
|
|
curl_off_t ulnow)
|
||
|
|
{
|
||
|
|
struct progress *memory = (struct progress *)clientp;
|
||
|
|
|
||
|
|
/* use the values */
|
||
|
|
|
||
|
|
return 0; /* all is good */
|
||
|
|
}
|
||
|
|
|
||
|
|
struct progress data;
|
||
|
|
|
||
|
|
/* pass struct to callback */
|
||
|
|
curl_easy_setopt(curl_handle, CURLOPT_XFERINFODATA, &data);
|
||
|
|
|
||
|
|
curl_easy_setopt(curl_handle, CURLOPT_XFERINFOFUNCTION, progress_callback);
|
||
|
|
.fi
|
||
|
|
.SH AVAILABILITY
|
||
|
|
Added in 7.32.0. This callback replaces \fICURLOPT_PROGRESSFUNCTION(3)\fP
|
||
|
|
.SH RETURN VALUE
|
||
|
|
Returns CURLE_OK.
|
||
|
|
.SH "SEE ALSO"
|
||
|
|
.BR CURLOPT_XFERINFODATA "(3), " CURLOPT_NOPROGRESS "(3), "
|