http://paypal.ebay.cn/integrationcenter/list__resource_2.html 

中文php開發簡介：http://www.paypal-china.org/wangzhai/197.html 
以下是ecshop中paypal的支付程式碼 

這段程式碼是向paypal支付介面提交的 
{{{ 

<form target="_blank" method="post" action="https://www.paypal.com/cgi-bin/webscr" style="text-align: center;"><input type="hidden" value="_xclick" name="cmd"/><input type="hidden" value="

[email protected]" name="business"/> //商家註冊的郵箱 
<input type="hidden" value="2009102370175" name="item_name"/><input type="hidden" value="2888.00" name="amount"/><input type="hidden" value="USD" name="currency_code"/><input type="hidden" value="http://127.0.0.1/ecshop/respond.php?code=paypal" name="return"/><input type="hidden" value="3" name="invoice"/><input type="hidden" value="utf-8" name="charset"/><input type="hidden" value="1" name="no_shipping"/><input type="hidden" value="" name="no_note"/><input type="hidden" value="http://127.0.0.1/ecshop/respond.php?code=paypal" name="notify_url"/><input type="hidden" value="2" name="rm"/><input type="hidden" value="http://127.0.0.1/ecshop/" name="cancel_return"/><input type="submit" value="立即使用 paypal 支付"/></form> 

}}} 

以下是官方提供的，接受到paypal傳回來的引數的，並且判斷是否支付成功。 

支援成功後由於提交表單中有 


<input type="hidden" value="http://127.0.0.1/ecshop/respond.php?code=paypal" name="return"/> 

paypal將會主動跳轉到espond.php?code=paypal這個頁面，頁面可現實以下POST得到的一些資料。 



複製程式碼程式碼如下:
// read the post from PayPal system and add 'cmd' 
$req = 'cmd=_notify-validate'; 

foreach ($_POST as $key => $value) { 
$value = urlencode(stripslashes($value)); 
$req .= "&$key=$value"; 
} 

// post back to PayPal system to validate 
$header .= "POST /cgi-bin/webscr HTTP/1.0\r\n"; 
$header .= "Content-Type: application/x-www-form-urlencoded\r\n"; 
$header .= "Content-Length: " . strlen($req) . "\r\n\r\n"; 
$fp = fsockopen ('ssl://www.paypal.com', 443, $errno, $errstr, 30); 

// assign posted variables to local variables 
$item_name = $_POST['item_name']; 
$item_number = $_POST['item_number']; 
$payment_status = $_POST['payment_status']; 
$payment_amount = $_POST['mc_gross']; 
$payment_currency = $_POST['mc_currency']; 
$txn_id = $_POST['txn_id']; 
$receiver_email = $_POST['receiver_email']; 
$payer_email = $_POST['payer_email']; 

if (!$fp) { 
// HTTP ERROR 
else { 
fputs ($fp, $header . $req); 
while (!feof($fp)) { 
$res = fgets ($fp, 1024); 
if (strcmp ($res, "VERIFIED") == 0) { 
// check the payment_status is Completed 
// check that txn_id has not been previously processed 
// check that receiver_email is your Primary PayPal email 
// check that payment_amount/payment_currency are correct 
// process payment 
} 
else if (strcmp ($res, "INVALID") == 0) { 
// log for manual investigation 
} 
} 
fclose ($fp); 
} 
?>