Just provide these three parameter to function and these will print all yahoo contacts for you..

function contactlist()
{
        $oauth_access_token = ' ';

    $oauth_token_secret = ' ' ;

    $session_id     = ' ' ;

    //prepare url

    $url = 'http://developer.messenger.yahooapis.com/v1/contacts';

    $url .= '?oauth_consumer_key='. CONSUMER_KEY;

    $url .= '&oauth_nonce='. uniqid(rand());

    $url .= '&oauth_signature='. CONSUMER_SECRET_KEY. '%26'. $oauth_token_secret;

    $url .= '&oauth_signature_method=PLAINTEXT';

    $url .= '&oauth_timestamp='. time();

    $url .= '&oauth_token='. urlencode($oauth_access_token);

    $url .= '&oauth_version=1.0';    

    $url .= '&sid='. $session_id;

    $url .= '&fields=%2Bpresence';

    $url .= '&fields=%2Bgroups';

    $url .= '&fields=%2Baddressbook';

    //additional header

    $header[] = 'Content-type: application/json; charset=utf-8';

    $rs = curl($url, 'get', $header);

    if (stripos($rs, 'contact') === false) return false;

    

    $js = json_decode($rs, true);

    print_r(json_encode($js['contacts']));

}

function curl($url, $method = 'get', $header = null, $postdata = null, $includeheader=FALSE, $timeout = 60)

{

    $s = curl_init();

    curl_setopt($s,CURLOPT_URL, $url);

    if ($header) 

curl_setopt($s,CURLOPT_HTTPHEADER, $header);

    /*if ($this->debug)*/

    curl_setopt($s,CURLOPT_VERBOSE, FALSE);

    curl_setopt($s,CURLOPT_TIMEOUT, $timeout);

    curl_setopt($s,CURLOPT_CONNECTTIMEOUT, $timeout);

    curl_setopt($s,CURLOPT_MAXREDIRS, 3);

    curl_setopt($s,CURLOPT_RETURNTRANSFER, true);

    curl_setopt($s,CURLOPT_FOLLOWLOCATION, 1);

    curl_setopt($s,CURLOPT_COOKIEJAR, 'cookie.txt');

    curl_setopt($s,CURLOPT_COOKIEFILE, 'cookie.txt'); 

    if(strtolower($method) == 'post')

    {

curl_setopt($s,CURLOPT_POST, true);

curl_setopt($s,CURLOPT_POSTFIELDS, $postdata);

    }

    else if(strtolower($method) == 'delete')

    {

curl_setopt($s,CURLOPT_CUSTOMREQUEST, 'DELETE');

    }

    else if(strtolower($method) == 'put')

    {

curl_setopt($s,CURLOPT_CUSTOMREQUEST, 'PUT');

curl_setopt($s,CURLOPT_POSTFIELDS, $postdata);

    }

    curl_setopt($s,CURLOPT_HEADER, $includeheader);  

    //curl_setopt($s,CURLOPT_USERAGENT, 'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1');

    curl_setopt($s, CURLOPT_SSL_VERIFYPEER, false);

    $html    = curl_exec($s);

    $status = curl_getinfo($s, CURLINFO_HTTP_CODE);

    curl_close($s);

    return $html;

}