curl_exec

(PHP 4 >= 4.0.2, PHP 5, PHP 7, PHP 8)

curl_exec — Perform a cURL session

Description

curl_exec(CurlHandle $handle): string|bool

Execute the given cURL session.

This function should be called after initializing a cURL session and all the options for the session are set.

Parameters

handle: A cURL handle returned by curl_init().

Return Values

On success, this function flushes the result directly to the stdout and returns true, or false on failure. However, if the CURLOPT_RETURNTRANSFER option is set, it will return the result on success, false on failure.

Warning

This function may return Boolean false, but may also return a non-Boolean value which evaluates to false. Please read the section on Booleans for more information. Use the === operator for testing the return value of this function.

Note:
Note that response status codes which indicate errors (such as 404 Not found) are not regarded as failure. curl_getinfo() can be used to check for these.

Changelog

Version	Description
8.0.0	`handle` expects a CurlHandle instance now; previously, a resource was expected.

Examples

Example #1 Fetching a web page

<?php
// create a new cURL resource
$ch = curl_init();

// set URL and other appropriate options
curl_setopt($ch, CURLOPT_URL, "http://www.example.com/");
curl_setopt($ch, CURLOPT_HEADER, 0);

// grab URL and pass it to the browser
curl_exec($ch);

// close cURL resource, and free up system resources
curl_close($ch);
?>

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User Contributed Notes 9 notes

down

117

David from Code2Design.com ¶

14 years ago

Just in case anyone is looking for a a couple of simple functions [to help automate cURL processes for POST and GET queries] I thought I'd post these.



<?php



/**

 * Send a POST requst using cURL

 * @param string $url to request

 * @param array $post values to send

 * @param array $options for cURL

 * @return string

 */

function curl_post($url, array $post = NULL, array $options = array())

{

    $defaults = array(

        CURLOPT_POST => 1,

        CURLOPT_HEADER => 0,

        CURLOPT_URL => $url,

        CURLOPT_FRESH_CONNECT => 1,

        CURLOPT_RETURNTRANSFER => 1,

        CURLOPT_FORBID_REUSE => 1,

        CURLOPT_TIMEOUT => 4,

        CURLOPT_POSTFIELDS => http_build_query($post)

    );



    $ch = curl_init();

    curl_setopt_array($ch, ($options + $defaults));

    if( ! $result = curl_exec($ch))

    {

        trigger_error(curl_error($ch));

    }

    curl_close($ch);

    return $result;

}



/**

 * Send a GET requst using cURL

 * @param string $url to request

 * @param array $get values to send

 * @param array $options for cURL

 * @return string

 */

function curl_get($url, array $get = NULL, array $options = array())

{    

    $defaults = array(

        CURLOPT_URL => $url. (strpos($url, '?') === FALSE ? '?' : ''). http_build_query($get),

        CURLOPT_HEADER => 0,

        CURLOPT_RETURNTRANSFER => TRUE,

        CURLOPT_TIMEOUT => 4

    );

    

    $ch = curl_init();

    curl_setopt_array($ch, ($options + $defaults));

    if( ! $result = curl_exec($ch))

    {

        trigger_error(curl_error($ch));

    }

    curl_close($ch);

    return $result;

}

?>

down

Anonymous ¶

18 years ago

Be careful when using curl_exec() and the CURLOPT_RETURNTRANSFER option. According to the manual and assorted documentation:
Set CURLOPT_RETURNTRANSFER to TRUE to return the transfer as a string of the return value of curl_exec() instead of outputting it out directly.

When retrieving a document with no content (ie. 0 byte file), curl_exec() will return bool(true), not an empty string. I've not seen any mention of this in the manual.

Example code to reproduce this:
<?php

    // fictional URL to an existing file with no data in it (ie. 0 byte file)
    $url = 'http://www.example.com/empty_file.txt';

    $curl = curl_init();
    
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_HEADER, false);

    // execute and return string (this should be an empty string '')
    $str = curl_exec($curl);

    curl_close($curl);

    // the value of $str is actually bool(true), not empty string ''
    var_dump($str);

?>

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turiyag ¶

7 years ago

Don't disable SSL verification! You don't need to, and it's super easy to stay secure! If you found that turning off "CURLOPT_SSL_VERIFYHOST" and "CURLOPT_SSL_VERIFYPEER" solved your problem, odds are you're just on a Windows box. Takes 2 min to solve the problem. Walkthrough here:

https://snippets.webaware.com.au/howto/stop-turning-off-curlopt_ssl_verifypeer-and-fix-your-php-config/

down

jpatta at digitalgamesystems dot com ¶

3 years ago

If you are looking the debug curl_exec, you may wish to log its details, and analyze the various time points during its execution.

before curl_exec:

<?php
    // this will produce a curl log
    curl_setopt($curl, CURLOPT_VERBOSE, true);
    curl_setopt($curl, CURLOPT_STDERR, fopen('/your/writable/app/logdir/curl.log', 'a+')); // a+ to append...
?>

after curl_exec, but before curl_close:

<?php
    // this will extract the timing information
    extract(curl_getinfo($curl)); // create metrics variables from getinfo
    $appconnect_time = curl_getinfo($curl, CURLINFO_APPCONNECT_TIME); // request this time explicitly
    $downloadduration = number_format($total_time - $starttransfer_time, 9); // format, to get rid of scientific notation
    $namelookup_time = number_format($namelookup_time, 9);
    $metrics = "CURL...: $url Time...: $total_time DNS: $namelookup_time Connect: $connect_time SSL/SSH: $appconnect_time PreTransfer: $pretransfer_time StartTransfer: $starttransfer_time Download: $downloadduration";
    error_log($metrics);  // write to php-fpm default www-error.log, or append it to same log as above with file_put_contents(<filename>, $metrics, FILE_APPEND)
?>

Happy debugging

down

-1

roman dot ivasyuk at gmail dot com ¶

16 years ago

<?php
class CurlRequest
{
    private $ch;
    /**
     * Init curl session
     * 
     * $params = array('url' => '',
     *                    'host' => '',
     *                   'header' => '',
     *                   'method' => '',
     *                   'referer' => '',
     *                   'cookie' => '',
     *                   'post_fields' => '',
     *                    ['login' => '',]
     *                    ['password' => '',]      
     *                   'timeout' => 0
     *                   );
     */                
    public function init($params)
    {
        $this->ch = curl_init();
        $user_agent = 'Mozilla/5.0 (Windows; U; 
Windows NT 5.1; ru; rv:1.8.0.9) Gecko/20061206 Firefox/1.5.0.9';
        $header = array(
        "Accept: text/xml,application/xml,application/xhtml+xml,
text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5",
        "Accept-Language: ru-ru,ru;q=0.7,en-us;q=0.5,en;q=0.3",
        "Accept-Charset: windows-1251,utf-8;q=0.7,*;q=0.7",
        "Keep-Alive: 300");
        if (isset($params['host']) && $params['host'])      $header[]="Host: ".$host;
        if (isset($params['header']) && $params['header']) $header[]=$params['header'];
        
        @curl_setopt ( $this -> ch , CURLOPT_RETURNTRANSFER , 1 );
        @curl_setopt ( $this -> ch , CURLOPT_VERBOSE , 1 );
        @curl_setopt ( $this -> ch , CURLOPT_HEADER , 1 );
        
        if ($params['method'] == "HEAD") @curl_setopt($this -> ch,CURLOPT_NOBODY,1);
        @curl_setopt ( $this -> ch, CURLOPT_FOLLOWLOCATION, 1);
        @curl_setopt ( $this -> ch , CURLOPT_HTTPHEADER, $header );
        if ($params['referer'])    @curl_setopt ($this -> ch , CURLOPT_REFERER, $params['referer'] );
        @curl_setopt ( $this -> ch , CURLOPT_USERAGENT, $user_agent);
        if ($params['cookie'])    @curl_setopt ($this -> ch , CURLOPT_COOKIE, $params['cookie']);

        if ( $params['method'] == "POST" )
        {
            curl_setopt( $this -> ch, CURLOPT_POST, true );
            curl_setopt( $this -> ch, CURLOPT_POSTFIELDS, $params['post_fields'] );
        }
        @curl_setopt( $this -> ch, CURLOPT_URL, $params['url']);
        @curl_setopt ( $this -> ch , CURLOPT_SSL_VERIFYPEER, 0 );
        @curl_setopt ( $this -> ch , CURLOPT_SSL_VERIFYHOST, 0 );
        if (isset($params['login']) & isset($params['password']))
            @curl_setopt($this -> ch , CURLOPT_USERPWD,$params['login'].':'.$params['password']);
        @curl_setopt ( $this -> ch , CURLOPT_TIMEOUT, $params['timeout']);
    }
    
    /**
     * Make curl request
     *
     * @return array  'header','body','curl_error','http_code','last_url'
     */
    public function exec()
    {
        $response = curl_exec($this->ch);
        $error = curl_error($this->ch);
        $result = array( 'header' => '', 
                         'body' => '', 
                         'curl_error' => '', 
                         'http_code' => '',
                         'last_url' => '');
        if ( $error != "" )
        {
            $result['curl_error'] = $error;
            return $result;
        }
        
        $header_size = curl_getinfo($this->ch,CURLINFO_HEADER_SIZE);
        $result['header'] = substr($response, 0, $header_size);
        $result['body'] = substr( $response, $header_size );
        $result['http_code'] = curl_getinfo($this -> ch,CURLINFO_HTTP_CODE);
        $result['last_url'] = curl_getinfo($this -> ch,CURLINFO_EFFECTIVE_URL);
        return $result;
    }
}
?>

Example of use:
<?php
..........
try
        {            
            $params = array('url' => 'http://www.google.com',
            'host' => '',
            'header' => '',
            'method' => 'GET', // 'POST','HEAD'
            'referer' => '',
            'cookie' => '',
            'post_fields' => '', // 'var1=value&var2=value
            'timeout' => 20
            );
            
            $this->curl->init($params);
            $result = $this->curl->exec();
            if ($result['curl_error'])    throw new Exception($result['curl_error']);
            if ($result['http_code']!='200')    throw new Exception("HTTP Code = ".$result['http_code']);
            if (!$result['body'])        throw new Exception("Body of file is empty");
            ...............
        }
        catch (Exception $e)
        {
                    echo $e->getMessage();
        }
?>

down

-1

hablutzel1 at gmail dot com ¶

10 years ago

Be always aware that CURLOPT_SSL_VERIFYPEER set to FALSE or 0 should never be used for production as it makes the link inmediately vulnerable to man-in-the-middle attack, still you can use it during development, but I would suggest that only if you KNOW what are you doing, otherwise spend some more time making requests to HTTPS sites work without resorting to set that option to FALSE or 0.

down

-3

lukasl at ackleymedia dot com ¶

18 years ago

Thank you for sharing this.  I was wondering why my result was 1.

To get around this in a safe way, this is how I check if the result is valid.

$ch = curl_init(); /// initialize a cURL session 
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, true);
$xmlResponse = curl_exec ($ch);
curl_close ($ch);

if (!is_string($xmlResponse) || !strlen($xmlResponse)) {
    return $this->_set_error( "Failure Contacting Server" );
} else {
    return $xmlResponse;
}

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-4

nagyp at hunaxon dot hu ¶

21 years ago

fyi:
It returns false if there's an error while executing the curl session, no matter how CURLOPT_RETURNTRANSFER is set.

down

-3

Roland ¶

4 years ago

To check for a timeout or error - 

 if (!$responsexml || !is_string($responsexml) || !strlen($responsexml) || strpos($responsexml, 'upstream request timeout') !== false) {
            return $this->sendRequest($request, $headers);
        }

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curl_exec

Description

Parameters

Return Values

Changelog

Examples

See Also

Found A Problem?

User Contributed Notes 9 notes