Connect to a URL using Basic Authentication : C/C++ using CURL

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <curl/curl.h>

struct string {

  char *ptr;

  size_t len;

};

void init_string(struct string *s) {

  s->len = 0;

  s->ptr = (char*)malloc(s->len+1);

  if (s->ptr == NULL) {

    fprintf(stderr, "malloc() failed\n");

    exit(EXIT_FAILURE);

  }

  s->ptr[0] = '\0';

}

size_t writefunc(void *ptr, size_t size, size_t nmemb, struct string *s)

{

  size_t new_len = s->len + size*nmemb;

  s->ptr = (char*)realloc(s->ptr, new_len+1);

  if (s->ptr == NULL) {

    fprintf(stderr, "realloc() failed\n");

    exit(EXIT_FAILURE);

  }

  memcpy(s->ptr+s->len, ptr, size*nmemb);

  s->ptr[new_len] = '\0';

  s->len = new_len;

  return size*nmemb;

}

int main(void)

{

  CURL *curl;

  CURLcode res;

  curl = curl_easy_init();

  if(curl) {

    struct string s;

const char *errmsg = NULL;

    init_string(&s);

curl_easy_setopt(curl, CURLOPT_URL, "http://192.168.1.1");

    curl_easy_setopt(curl, CURLOPT_USERPWD, "admin:admin");

    curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errmsg);

curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writefunc);

    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &s); 

    res = curl_easy_perform(curl);

/* Validate the Connection */

if(res != CURLE_OK)

    {

          printf( "curl_easy_perform() failed: %s\nError Message: %s\n", curl_easy_strerror( res ), errmsg );

    }

    //printf("%s\n", s.ptr);

    free(s.ptr);

    /* always cleanup */

    curl_easy_cleanup(curl);

  }

  return 0;

}