How to download a file by libcurl

[adalwin]

Hi there. I have just started c++ . I want to download a file by libcurl but I got error everytime. I try this codes. I have downloaded libcurl but I'm not what should I do.
I'm using bloodshed dev c++ 4.9.9.2 . thanks

  #define CURL_STATICLIB
#include <stdio.h>
#include <curl/curl.h>
#include <curl/types.h>
#include <curl/easy.h>
#include <string>

size_t write_data(void *ptr, size_t size, size_t nmemb, FILE *stream) {
    size_t written;
    written = fwrite(ptr, size, nmemb, stream);
    return written;
}

int main(void) {
    CURL *curl;
    FILE *fp;
    CURLcode res;
    char *url = "http://localhost/aaa.txt";
    char outfilename[FILENAME_MAX] = "C:\\bbb.txt";
    curl = curl_easy_init();
    if (curl) {
        fp = fopen(outfilename,"wb");
        curl_easy_setopt(curl, CURLOPT_URL, url);
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, fp);
        res = curl_easy_perform(curl);
        curl_easy_cleanup(curl);
        fclose(fp);
    }
    return 0;
}

[modoran]

This works for me:

#define CURL_STATICLIB
#include <stdio.h>
#include <curl/curl.h>
#include <string>

size_t write_data(void *ptr, size_t size, size_t nmemb, FILE *stream)
{
    size_t written;
    written = fwrite(ptr, size, nmemb, stream);
    return written;
}

int main(void)
{
    CURL *curl;
    FILE *fp;
    CURLcode res;
    char *url = "http://localhost/aaa.txt";
    char outfilename[FILENAME_MAX] = "C:\\bbb.txt";
    curl = curl_easy_init();
    if (curl)
    {
        fp = fopen(outfilename,"wb");
        curl_easy_setopt(curl, CURLOPT_URL, url);
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, fp);
        curl_easy_setopt (curl, CURLOPT_VERBOSE, 1L);
        res = curl_easy_perform(curl);
        curl_easy_cleanup(curl);
        fclose(fp);
    }
    return 0;
}

Beware that for writing "C:\\bbb.txt" you need administrator privileges.

[EisenhowerPDF]

Hi, as I am a developer using Visual Basic programming language, I cannot take part in this post on posting and sharing the C++ codes on downloading file, including image and document file. I can demonstrate how to download file, for example, how to download image file from url at the very beginning of an image reading and processing project. It goes in the similar way with downloading a file by libcurl.

http://www.rasteredge.com/how-to/vb-net-imaging/download-from-url/

Public Shared Function GetImageFromURL(url As String, dec As BaseDecoder) As REImage

And more file loading topics and posts on:

http://www.rasteredge.com/how-to/vb-net-imaging/open-save-file/