<?php
/*
 * Script that posts multiple RSS feeds to twitter
 * 
 * Use this with crontab (it works with CLI too)
 * to post your feed's content to twitter
 * 
 * A tutorial by:
 * http://www.webdigity.com/
 * 
 */
 
$settings ['twitter-username'] = 'USERNAME';// Your twitter username
$settings ['twitter-password'] = 'PASSWORD';// Your twitter password
$settings ['feed-url'] ='FEED';//The url of the feed we are going to post to twitter
 
set_time_limit(0);//We need this because otherwise php will probably time out
//Let's see if we have the curl library
if (!extension_loaded('curl') && !dl('curl.' . (stristr(php_OS, 'WIN')?'dll':'so'))) die( 'Curl is not loaded' );
//Now we need a file to log the last entry so we wont post it again
$file = dirname(__FILE__) . '/feed.log.txt';
if ( !file_exists( $file ) ){
	$fp = @fopen( $file, 'w');
	if (! $fp )
		die( 'Could not write to log file. Check your permissions.' );
	fclose( $fp );
} else
	if ( !is_writable( $file ) ) die( 'Could not write to log file. Check your permissions.' );
//Fetch the RSS feed
$ch = curl_init( $settings['feed-url'] );
curl_setopt($ch, CURLOPT_TIMEOUT, 10);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$feed = simplexml_load_string ( curl_exec($ch) );
curl_close($ch);
//Parse the feed
$messages = array();//Here we will store all the messages that we are going to post to twitter
foreach( $feed->channel->item as $item ){
	$title = $item->title; // If you want to fetch the description instead use $item->description
	$url = $item->link;
	//Have we already posted that?
	if ( $url == file_get_contents($file) )	break;
	//Now do the actual posting.
	//First we need to shorten the url
	$ch = curl_init( 'http://twt.gs/?url='.$url.'&user='.$settings['twitter-username'].'&pass='.$settings['twitter-password'] );
	curl_setopt($ch, CURLOPT_TIMEOUT, 10);
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
	$shortURL = curl_exec($ch);
	$resp = curl_getinfo($ch, CURLINFO_HTTP_CODE);
	curl_close($ch);
	if ( $resp != '200' )
		die('Problem with the url shortening service. Check back later. Error: '.$shortURL);
	//Now Calculate the twit message
	$cnt = 140 - strlen($shortURL) - 1;
	$messages [] = strlen($title) <= $cnt ? $title . ' ' . $shortURL : substr($title,0,$cnt-3).'... '.$shortURL;
	$lastURL = empty($lastURL) ? $url : $lastURL;
}
//Post to twitter
while( $message = array_pop($messages) ){
	$ch = curl_init('http://twitter.com/statuses/update.xml');
	curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
	curl_setopt($ch, CURLOPT_POST, 1);
	curl_setopt($ch, CURLOPT_POSTFIELDS, 'status='.urlencode($message));
	curl_setopt($ch, CURLOPT_USERPWD, $settings['twitter-username'].':'.$settings['twitter-password']);
 
	$response = curl_exec($ch);
	$resp = curl_getinfo($ch, CURLINFO_HTTP_CODE);
	curl_close($ch);
	if ( $resp != '200' )
		die('Problem with twitter. We should try later. Twitter reported: '.$response);
	else
		sleep(5);//Sleep 5 seconds before the next update
}
$fp = fopen($file, 'w');
fwrite($fp, $lastURL);
fclose($fp);
?>