Accessing the Twitter Streaming API with C

Question

I'm trying to access the Streaming API with C, and am using the following 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, "http://stream.twitter.com/1/statuses/sample.json?delimited=length -uJEggers2:password");
    res = curl_easy_perform(curl);
    printf("results: %c", res);
    /* always cleanup */ 
    curl_easy_cleanup(curl);
  }
  return 0;
}

This prints nothing upon execution, what am I doing wrong? Thanks. EDIT: The Code works when I use google.com as the URL, but it just seems to be an issue with the Streaming API. Any Ideas?

Does this work even without CURLOPT_HTTPAUTH? – neilmarion Nov 12 '11 at 02:31 — neilmarion, Nov 12 '11 at 02:31

Flavio · Answer 1 · 2011-01-19T17:15:12.870

3

The function curl_easy_perform() only returns the error code. To actually retrieve the data you'll have to set CURLOPT_WRITEFUNCTION to your own callback function.

Edit: You also can't use " -uJEggers2:password" in the URL string, you'll have to set the authentication options using CURLOPT_HTTPAUTH, CURLOPT_USERNAME and CURLOPT_PASSWORD.

edited Jan 19 '11 at 17:15

answered Jan 19 '11 at 16:56

Flavio

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That couldn't be right, when I use google.com instead of the Streaming API url the source code is printed. Any ideas? – Jan 19 '11 at 16:59
Curl probably writes the output to stdout when you haven't specified your own WRITEFUNCTION. See http://stackoverflow.com/questions/2329571/c-libcurl-get-output-into-a-string for sample code. – Flavio Jan 19 '11 at 17:00
Also see my edit regarding user authentication, this is probably why you didn't see any output. You will still have to use a writefunction if you want to work with the output, otherwise it's just libcurl printing the output to stdout. – Flavio Jan 19 '11 at 17:11
Could you please present here how you have solved this. I do not have an idea how should I set CURLOPT_HTTPAUTH to allow Twitter Streaming with C. Thanks! – neilmarion Nov 12 '11 at 02:33

gravitron · Answer 2 · 2011-01-19T17:14:54.163

0

edit:I think the difference between using google.com and the twitter API is that in this case you are trying to specify a password with " -u user:pass". Nowhere in the CURL API do I see this technique mentioned.

Instead pass the user and pass separately with an additional curl_easy_setopt(curl, CURLOPT_USERPWD, "user:pass") as described in section "NAMES and PASSWORDS OPTIONS" at http://curl.haxx.se/libcurl/c/curl_easy_setopt.html

edited Jan 19 '11 at 17:14

answered Jan 19 '11 at 16:51

gravitron

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The Code works when I use google.com as the address, it prints the source code. It's just an issue with the Streaming API. Any ideas? – Jan 19 '11 at 16:56
You said in the question that nothing is printed. Do you mean nothing except for "results: __"? – gravitron Jan 19 '11 at 17:03
see edit regarding user authentication, same conclusion as Flavio. – gravitron Jan 19 '11 at 17:16
1

Glad it works. Please consider upvoting and choosing an answer, it'd support people answering your follow-up questions. – gravitron Jan 19 '11 at 20:59

Accessing the Twitter Streaming API with C

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