Return to CURLOPT_PROGRESSFUNCTION.3 CVS log

Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / curl / docs / libcurl / opts

Annotation of embedaddon/curl/docs/libcurl/opts/CURLOPT_PROGRESSFUNCTION.3, revision 1.1

1.1     ! misho       1: .\" **************************************************************************
        !             2: .\" *                                  _   _ ____  _
        !             3: .\" *  Project                     ___| | | |  _ \| |
        !             4: .\" *                             / __| | | | |_) | |
        !             5: .\" *                            | (__| |_| |  _ <| |___
        !             6: .\" *                             \___|\___/|_| \_\_____|
        !             7: .\" *
        !             8: .\" * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
        !             9: .\" *
        !            10: .\" * This software is licensed as described in the file COPYING, which
        !            11: .\" * you should have received as part of this distribution. The terms
        !            12: .\" * are also available at https://curl.haxx.se/docs/copyright.html.
        !            13: .\" *
        !            14: .\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
        !            15: .\" * copies of the Software, and permit persons to whom the Software is
        !            16: .\" * furnished to do so, under the terms of the COPYING file.
        !            17: .\" *
        !            18: .\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
        !            19: .\" * KIND, either express or implied.
        !            20: .\" *
        !            21: .\" **************************************************************************
        !            22: .\"
        !            23: .TH CURLOPT_PROGRESSFUNCTION 3 "March 23, 2020" "libcurl 7.70.0" "curl_easy_setopt options"
        !            24: 
        !            25: .SH NAME
        !            26: CURLOPT_PROGRESSFUNCTION \- callback to progress meter function
        !            27: .SH SYNOPSIS
        !            28: #include <curl/curl.h>
        !            29: 
        !            30: int progress_callback(void *clientp,
        !            31:                       double dltotal,
        !            32:                       double dlnow,
        !            33:                       double ultotal,
        !            34:                       double ulnow);
        !            35: 
        !            36: CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROGRESSFUNCTION, progress_callback);
        !            37: .SH DESCRIPTION
        !            38: Pass a pointer to your callback function, which should match the prototype
        !            39: shown above.
        !            40: 
        !            41: We encourage users to use the newer \fICURLOPT_XFERINFOFUNCTION(3)\fP instead,
        !            42: if you can.
        !            43: 
        !            44: This function gets called by libcurl instead of its internal equivalent with a
        !            45: frequent interval. While data is being transferred it will be called very
        !            46: frequently, and during slow periods like when nothing is being transferred it
        !            47: can slow down to about one call per second.
        !            48: 
        !            49: \fIclientp\fP is the pointer set with \fICURLOPT_PROGRESSDATA(3)\fP, it is not
        !            50: used by libcurl but is only passed along from the application to the callback.
        !            51: 
        !            52: The callback gets told how much data libcurl will transfer and has
        !            53: transferred, in number of bytes. \fIdltotal\fP is the total number of bytes
        !            54: libcurl expects to download in this transfer. \fIdlnow\fP is the number of
        !            55: bytes downloaded so far. \fIultotal\fP is the total number of bytes libcurl
        !            56: expects to upload in this transfer. \fIulnow\fP is the number of bytes
        !            57: uploaded so far.
        !            58: 
        !            59: Unknown/unused argument values passed to the callback will be set to zero
        !            60: (like if you only download data, the upload size will remain 0). Many times
        !            61: the callback will be called one or more times first, before it knows the data
        !            62: sizes so a program must be made to handle that.
        !            63: 
        !            64: If your callback function returns CURL_PROGRESSFUNC_CONTINUE it will cause
        !            65: libcurl to continue executing the default progress function.
        !            66: 
        !            67: Returning any other non-zero value from this callback will cause libcurl to
        !            68: abort the transfer and return \fICURLE_ABORTED_BY_CALLBACK\fP.
        !            69: 
        !            70: If you transfer data with the multi interface, this function will not be
        !            71: called during periods of idleness unless you call the appropriate libcurl
        !            72: function that performs transfers.
        !            73: 
        !            74: \fICURLOPT_NOPROGRESS(3)\fP must be set to 0 to make this function actually
        !            75: get called.
        !            76: .SH DEFAULT
        !            77: By default, libcurl has an internal progress meter. That's rarely wanted by
        !            78: users.
        !            79: .SH PROTOCOLS
        !            80: All
        !            81: .SH EXAMPLE
        !            82: https://curl.haxx.se/libcurl/c/progressfunc.html
        !            83: .SH AVAILABILITY
        !            84: Always
        !            85: .SH RETURN VALUE
        !            86: Returns CURLE_OK.
        !            87: .SH "SEE ALSO"
        !            88: .BR CURLOPT_VERBOSE "(3), " CURLOPT_NOPROGRESS "(3), "