Re: Web pages extraction & Libcurl
 
On Nov 9, 12:54 pm, Choi <Evil.C...@gmail.com> wrote:
On Nov 9, 11:50 am, Choi <Evil.C...@gmail.com> wrote:
Good morning.
I've tried to extract, using libcurl, web pages but it failed. There
is no compilation error concerning the class I wrote, but the problems
appear when I compile a main method which calls this class.
My class :
**********************************libcurl_tools.h
#include <curl/curl.h>
struct  MemoryStruct {
        char *memory;
        size_t size;
};
class libcurl_tools {
        CURL * curl_handle;
        MemoryStruct chunk;
        public:
        libcurl_tools();
        void init();
        bool close();
        void set_referrer(std::string, CURL *);
        std::string perform(std::string, CURL *);
};
**********************************libcurl_tools.cpp
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <curl/curl.h>
#include <curl/types.h>
#include <curl/easy.h>
#include <iostream> // pour std::cout
#include <string>   // pour std::string
#include "libcurl_tools.h"
libcurl_tools::libcurl_tools() {}
static void *myrealloc(void *ptr, size_t size)
{
        /* There might be a realloc() out there that doesn't like reall=
ocing
           NULL pointers, so we take care of it here */
        if(ptr)
                return realloc(ptr, size);
        else
                return malloc(size);
}
static size_t WriteMemoryCallback(void *ptr, size_t size, size_t
nmemb, void *data)
{
        size_t realsize = size * nmemb;
        struct MemoryStruct *mem = (struct MemoryStruct *)data;
        mem->memory = (char *)myrealloc(mem->memory, mem->size + real=
size +
1);
        if (mem->memory) {
                memcpy(&(mem->memory[mem->size]), ptr, realsize);
                mem->size += realsize;
                mem->memory[mem->size] = 0;
        }
        return realsize;
}
void libcurl_tools::set_referrer(std::string referer, CURL
*curl_handle ) {
        curl_easy_setopt(curl_handle, CURLOPT_REFERER, referer.c_str());
}
//initialise la connection
void libcurl_tools::init() {
        chunk.memory=NULL; /* we expect realloc(NULL, size) to work */
        chunk.size = 0;    /* no data at this point */
        curl_global_init(CURL_GLOBAL_ALL);
        /* init the curl session */
        curl_handle = curl_easy_init();
}
//t=E9l=E9charge l'url en argument
std::string libcurl_tools::perform(std::string url , CURL
*curl_handle) {
        /* specify URL to get */
        curl_easy_setopt(curl_handle, CURLOPT_URL, url.c_str());
        /* send all data to this function  */
        curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION,
WriteMemoryCallback);
        /* we pass our 'chunk' struct to the callback function */
        curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, (void *)&chunk=
);
        /* some servers don't like requests that are made without a use=
r-
agent
           field, so we provide one */
        curl_easy_setopt(curl_handle, CURLOPT_USERAGENT, "libcurl-agent/
1.0");
        /* get it! */
        curl_easy_perform(curl_handle);
        /* cleanup curl stuff */
        curl_easy_cleanup(curl_handle);
        /*
         * Now, our chunk.memory points to a memory block that is chunk=
..size
         * bytes big and contains the remote file.
         *
         * Do something nice with it!
         *
         * You should be aware of the fact that at this point we might =
have
an
         * allocated data block, and nothing has yet deallocated that d=
ata.
So when
         * you're done with it, you should free() it as a nice applicat=
ion.
         */
        //return chunk.memory; // les 2 ont l'air de marcher (pour le
moment...)
        return std::string(chunk.memory);
}
bool libcurl_tools::close() {
        if(chunk.memory)
                free(chunk.memory);
        return 0;
}
*********************************** test.cpp which includes the main()
#include <iostream>
#include <string>
#include <sstream>
#include "libcurl_tools.h"
//#include <stdio.h>
using namespace std;
int main()
{
 libcurl_tools e();
    e.init();
    std::string chaine;
    std:: string s = "www.yahoo.com";
 chaine = e.perform(s);
   e.close();
}
There are 3 compilation errors concerning the calls of init(),
perform() and close() methods, and I really don't know why it happens.
I wish you could help me guys...
Thanks
If it can help, the errors are similar to :
 test.cpp:91: erreur: request for member =ABinit" in =ABe", which is of
non-class type =ABlibcurl_tools ()()"
Thanks Alan, I modified libcurl_tools e(); -> libcurl_tools e; I
didn't see that stupid mistake !!!! I also modified the class. Now it
works !!!!
Thanks a lot