progressfunc.c
/*************************************************************************** * _ _ ____ _ * 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 * ***************************************************************************/ /* <DESC> * Use the progress callbacks, old and/or new one depending on available * libcurl version. * </DESC> */ #include <stdio.h> #include <curl/curl.h> #define MINIMAL_PROGRESS_FUNCTIONALITY_INTERVAL 3000000 #define STOP_DOWNLOAD_AFTER_THIS_MANY_BYTES 6000 struct myprogress { curl_off_t lastruntime; /* type depends on version, see above */ CURL *curl; }; /* this is how the CURLOPT_XFERINFOFUNCTION callback works */ static int xferinfo(void *p, curl_off_t dltotal, curl_off_t dlnow, curl_off_t ultotal, curl_off_t ulnow) { struct myprogress *myp = (struct myprogress *)p; CURL *curl = myp->curl; curl_off_t curtime = 0; curl_easy_getinfo(curl, CURLINFO_TOTAL_TIME_T, &curtime); /* under certain circumstances it may be desirable for certain functionality to only run every N seconds, in order to do this the transaction time can be used */ if((curtime - myp->lastruntime) >= MINIMAL_PROGRESS_FUNCTIONALITY_INTERVAL) { myp->lastruntime = curtime; fprintf(stderr, "TOTAL TIME: %lu.%06lu\r\n", (unsigned long)(curtime / 1000000), (unsigned long)(curtime % 1000000)); } fprintf(stderr, "UP: %lu of %lu DOWN: %lu of %lu\r\n", (unsigned long)ulnow, (unsigned long)ultotal, (unsigned long)dlnow, (unsigned long)dltotal); if(dlnow > STOP_DOWNLOAD_AFTER_THIS_MANY_BYTES) return 1; return 0; } int main(void) { CURL *curl; CURLcode res = CURLE_OK; struct myprogress prog; curl = curl_easy_init(); if(curl) { prog.lastruntime = 0; prog.curl = curl; curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/"); curl_easy_setopt(curl, CURLOPT_XFERINFOFUNCTION, xferinfo); /* pass the struct pointer into the xferinfo function */ curl_easy_setopt(curl, CURLOPT_XFERINFODATA, &prog); curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0L); res = curl_easy_perform(curl); if(res != CURLE_OK) fprintf(stderr, "%s\n", curl_easy_strerror(res)); /* always cleanup */ curl_easy_cleanup(curl); } return (int)res; }
Notice
This source code example is simplified and ignores return
codes and error checks to a large extent. We do this to highlight the libcurl
function calls and related options and reduce unrelated code.
A real-world application will of course properly check every return value and exit correctly at the first serious error.