如果CURLOPT_RETURNTRANSFER设置为true，则cURL PHP无效

Question

I try to extract the HTML of a site via cURL for PHP. Normally it works fine, but there are some website the response is empty. For example if I execute the following script for the URL alditalk.de:

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'http://www.alditalk.de/');
curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.1) Gecko/20061204 Firefox/4");
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, false);
$data = curl_exec($ch);
curl_close($ch);

In this case the variable $data is empty. The strange thing about that is if I change curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); to curl_setopt($ch, CURLOPT_RETURNTRANSFER, false); the website will be printed on the screen. The problem is, I need the content in a variable for further operations.

I tried it locally on WAMPP as well on my Hoster. I also tried to set some header information without success. There are also no errors. Are there any solutions?

Answer 1

Its working for me. i think you are not enable the curl extension.

Since you're using XAMPP, uncomment the line

;extension=php_curl.dll

in xampp\\apache\\bin\\php.ini , and then restart the Apache service.

NB: In newer XAMPP versions, PHP has moved to root xampp folder xampp\\php\\php.ini .

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Steps in WAMP SERVER

The steps are as follows :

1. Close WAMP (if running)
2. Navigate to WAMP\\bin\\php\\(your version of php)\\
3. Edit php.ini
4. Search for curl, uncomment extension=php_curl.dll
5. Navigate to WAMP\\bin\\Apache\\(your version of apache)\\bin\\
6. Edit php.ini
7. Search for curl, uncomment extension=php_curl.dll
8. Save both
9. Restart WAMP

Answer 2

Its working fine for me ..I think the curl extension is not enabled well ..Are you using xampp ??

Go to http://www.anindya.com/php-5-4-3-and-php-5-3-13-x64-64-bit-for-windows/ 

and download the curl version that is same as your php version..

Answer 3

This doesn't directly answer your question, but it offers a bit of a workaround: Could you consider using ob_start() and associated functions to capture the output that you are able to get?

The idea above is a hacky way to solve it, of course. Before falling back on ob_start(), I would suggest double-checking all variable names, ini settings, etc., since it's always possible that you're doing something like accidentally trying to access the contents of $daya rather than $data -- which is precisely the kind of typo I just spent 45 minutes on in my own script. Fixing my variable name fixed the the misbehavior that had originally led me to this question.

Hoping that helps somebody. Cheers!