PHP, Curl - Check for empty result

Question

Most of the time the URL will return some information, however when no information is returned, I want to return a string 'Empty Result', so not to be passing an empty string to SimpleXmlElement function as this seems to produce an error.

How do I check for a empty/null response from Curl?

    // Get cURL resource
    $curl = curl_init();

    // Set some options - we are passing in a useragent too here
    curl_setopt_array($curl, array(
        CURLOPT_RETURNTRANSFER => 1,
        CURLOPT_URL => $searchString,
        CURLOPT_USERAGENT => 'Codular Sample cURL Request',
        CURLOPT_FOLLOWLOCATION, true
    ));
    // Send the request & save response to $resp
    $result = curl_exec($curl);

    // Close request to clear up some resources
    curl_close($curl);

    if($result === null)
    {
        return 'Empty Result';
    }

    $doc = new SimpleXmlElement($result, LIBXML_NOCDATA);

[`curl_exec()`](http://php.net/curl_exec) will return either `String` or `FALSE` so did you consider (for) checking these two types? — kero, Aug 19 '14 at 15:19
I don't think it will every return `NULL`. If it's successful it returns a string, if it fails it returns `FALSE`. — Barmar, Aug 19 '14 at 15:19
Change this line `if($result === null)` to this: `if(!$result)` — hindmost, Aug 19 '14 at 15:20

score 3 · Accepted Answer · edited May 23 '17 at 12:23

3

Try:

if(!$result || strlen(trim($result)) == 0)
{
    return 'Empty Result';
}

Will return "Empty Result" on failure or if a blank response is encountered.

Alternatively, you could handle your XML errors like so.

edited May 23 '17 at 12:23

Community

1
1

answered Aug 19 '14 at 15:22

Wayne Whitty

19,513
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score 1 · Answer 2 · answered Aug 19 '14 at 15:22

Give this a shot

// Get cURL resource
$curl = curl_init();

// Set some options - we are passing in a useragent too here
curl_setopt_array($curl, array(
    CURLOPT_RETURNTRANSFER => 1,
    CURLOPT_URL => $searchString,
    CURLOPT_USERAGENT => 'Codular Sample cURL Request',
    CURLOPT_FOLLOWLOCATION, true
));
// Send the request & save response to $resp
$result = curl_exec($curl);

// Close request to clear up some resources
curl_close($curl);

if( $result === null || $result == FALSE || $result == '' )
{
    return 'Empty Result';
}

$doc = new SimpleXmlElement($result, LIBXML_NOCDATA);

PHP, Curl - Check for empty result

2 Answers2