CURL in PHP does not send a POST query - php

Question

I am trying to send a POST query to a web-page, but unfortunately it does not work. Below is my code:
<?php
$url_ref = "http://www.wunschgrundstueck.de/immobilien/wohnung-suchen.html?sp_was=wohnungen_m&lses=1";
$url = "http://www.wunschgrundstueck.de/immobilien/suchergebnis/wohnungen.html";
$fields = array(
'id_land' => 'DEU',
'id_bundesland' => '7',
'id_landkreis'=> '186',
'id_gemeinde'=>'5234',
'su_anb' => '0',
'sp_was' => 'wohnungen_m',
'sp_wo' => 'Frankfurt am Main',
'sp_ort_land' => 'DEU',
'sp_ort_bula' => '7',
'sp_ort_lakr' => '186',
'sp_ort_geme' => '5234',
'sp_ort_teil' => '0',
'sp_ort_umkreis' => '0',
'miete' => 'on',
'su_wohn_preis_miete_art' => '1',
);
$fields_string;
//url-ify the data for the POST
foreach($fields as $key=>$value) { $fields_string .= $key.'='.$value.'&'; }
rtrim($fields_string,'&');
echo $fields_string;
//open connection
$curl = curl_init($url);
curl_setopt($curl, CURLOPT_POST, true);
curl_setopt($curl, CURLOPT_HEADER, 0);
curl_setopt($curl, CURLOPT_REFERER, $url_ref);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($curl, CURLOPT_AUTOREFERER, true);
curl_setopt($curl,CURLOPT_USERAGENT,'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1312.52 Safari/537.17');
curl_setopt($curl,CURLOPT_POST,count($fields));
curl_setopt($curl,CURLOPT_POSTFIELDS,$fields_string);
$result = curl_exec($curl);
?>
Unfortunately, it seems that I do something wrong because the result that is returned is not the one I am expecting. What puzzles me a lot is that if I send the same request using the LiveHTTP headers plugin for firefox then I get the correct result. I then tried to send the request with WFetch, and then I receive a 301 Moved permanently error. This is the HTTP Post headers/fields that I tested with HTTPLive from firefox where it works correctly and with WFetch where I get the 301 error.
Host: www.wunschgrundstueck.de\r\n
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:26.0) Gecko/20100101 Firefox/26.0\r\n
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\r\n
Accept-Language: de-de,de;q=0.8,en-us;q=0.5,en;q=0.3\r\n
Accept-Encoding: gzip, deflate\r\n
Referer: http://www.wunschgrundstueck.de/immobilien/landkreis_frankfurt_am_main/wohnungen.html?s=1\r\n
Connection: keep-alive\r\n
Content-Type: application/x-www-form-urlencoded\r\n
\r\n
id_land=DEU&id_bundesland=7&id_landkreis=186&id_gemeinde=&id_ortsteil=&gemeid_bereich=&su_suchart=erweitert&su_anb=0&sp_was=wohnungen&sp_wo=&sp_ort_land=DEU&sp_ort_bula=7&sp_ort_lakr=186&sp_ort_geme=0&sp_ort_teil=0&sp_wo_ausl=&miete=on&su_wohnfl_wohn_von=&su_wohnfl_wohn_bis=&su_wohn_preis_von_kauf=&su_wohn_preis_bis_kauf=&su_wohn_preis_miete_art=1&su_wohn_preis_von_miete=&su_wohn_preis_bis_miete=&su_zimmer_wohn_anz_von=&su_zimmer_wohn_anz_bis=&su_filter_wohntyp=&su_wohn_etage_von=&su_wohn_etage_bis=&su_wohn_filter_anzbad=&su_wohn_filter_anzschlaf=&su_wohn_filter_baf_det=&su_wohn_filter_moebliert=&submit=Ergebnisse+zeigen+%BB\r\n
\r\n

Answer 1

I don't see you urlencode the key-value pairs you assembly $fields_string from. This might be the reason why you're not getting expected results as some fields have spaces that need to be urlencoded.
That said, you don't need to assembly the post data manually, curl will do that for you if provided an array:
curl_setopt($curl, CURLOPT_POSTFIELDS, $fields);
On a sidenote: 301 is not an error; it's a redirection code, which WFetch doesn't follow automatically, while your browser does.