Reading XML returned from a POST

Hello, im using a C program with libcurl to send a POST. The server reads my POST and return a XML file, that is printed in the terminal when i execute the program. How can i put the lines from this XML into variables in my C program? It doesnt seem to write this info anywhere?!

Code:

#include <stdio.h>
#include <curl/curl.h>
  
int main(void){
    CURL *curl;
    CURLcode res;
  
    curl = curl_easy_init();
    if(curl) {
       
        curl_easy_setopt(curl, CURLOPT_URL, "www.xxx.zzz.php");        
        curl_easy_setopt(curl, CURLOPT_POSTFIELDS, "in_chkcacic=chkinfo");  
      
        res = curl_easy_perform(curl);

        curl_easy_cleanup(curl);
    }
    return 0;
}

man 3 libcurl will tell you how. You'll have to write a custom handler for the data, otherwise, the default handler will write the output to stdout.

(FYI, I've never written a program with libcurl, and have been wanting to do this. So I took yours, figured out how to link it with Xcode, read the man pages, and Viola! It worked.)

Todd

I read the man page, but i cant make it work properly... Please correct me if im wrong. If i want to get the POST answer in a variable (char *) but the options CURLOPT_WRITEFUNCTION and CURLOPT_WRITEDATA are said to write in files...

I also dont know which one i have to use, or if i have to use both. According to the manual:

"If you're using libcurl as a win32 DLL, you MUST use the CURLOPT_WRITEFUNCTION if you set this option (CURLOPT_WRITEDATA) or you will experience crashes."

This is the example i made using the options, based on some examples. Is it correct? How can i get the info i need?

Code:

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


struct MemoryStruct {
    char *memory;
    size_t size;
};

static void *myrealloc(void *ptr, size_t size) {
    /* There might be a realloc() out there that doesn't like reallocing
       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 + realsize + 1);
    if (mem->memory) {
	memcpy(&(mem->memory[mem->size]), ptr, realsize);
	mem->size += realsize;
	mem->memory[mem->size] = 0;
    }
    return realsize;
}


int main(void){
    CURL *curl;
    CURLcode res;
  
    struct MemoryStruct chunk;
 
    chunk.memory=NULL; 
    chunk.size = 0;   

    curl = curl_easy_init();
    
    if(curl) {        
        curl_easy_setopt(curl, CURLOPT_URL, "www.xxx.zzz.php");

	        
        curl_easy_setopt(curl, CURLOPT_POSTFIELDS, "in_chkcacic=chkinfo");
	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
	curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)&chunk);  
	       
        res = curl_easy_perform(curl);
          
        curl_easy_cleanup(curl);
    }
    return 0;
}