Is it possible to get partial response using PHP cURL? - php

Question

Here is my code
$url = "partial_response.php";
$sac_curl = curl_init();
curl_setopt($sac_curl, CURLOPT_HTTPGET, true);
curl_setopt($sac_curl, CURLOPT_URL, $url);
curl_setopt($sac_curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($sac_curl, CURLOPT_HEADER, false);
curl_setopt($sac_curl, CURLOPT_TIMEOUT, 11);
$resp = curl_exec($sac_curl);
curl_close($sac_curl);
echo $resp;
Partial_response.php
header( 'Content-type: text/html; charset=utf-8' );
echo 'Job waiting ...<br />';
for( $i = 0 ; $i < 10 ; $i++ )
{
echo $i . '<br/>';
flush();
ob_flush();
sleep(1);
}
echo 'End ...<br/>';
From the about code am trying to get a partial response from partial_response.php. what I want is, I need curl to return me "Job waiting.." alone instead of waiting for the partial_response.php to complete the loop and return the entire data. so when I reduce CURLOPT_TIMEOUT below 11 i dont get any response at all. Kindly clarify my doubt.
Thanks in advance.

Answer 1

I later realized that cURL could not do what I want, I used stream_context_get_options
to achieve what I wanted. Here it is, http://www.php.net/manual/en/function.stream-context-get-options.php.

Answer 2

No, I'm afraid not. At least not that I know of any, this is simply because PHP is a synchronous language, meaning you cannot "skip" tasks. (I.e. curl_exec() will always - no matter what - be executed until the request is completed)

Answer 3

I'm not sure abut the timeout, but you can get partial response using cURL by using the CURLOPT_WRITEFUNCTION flag:
curl_setopt($ch, CURLOPT_WRITEFUNCTION, $callback);
Where $ch is the Curl handler, and $callback is the callback function name. This command will stream response data from remote site. The callback function can look something like:
$result = '';
$callback = function ($ch, $str) {
global $result;
//$str has the chunks of data streamed back.
$result .= $str;
// here you can mess with the stream data either with $result or $str.
// i.e. look for the "Job waiting" string and terminate the response.
return strlen($str);//don't touch this
};
If not interrupted at the end $result will contain all the response from remote site.
So combining everything will look something like:
$result = '';
$callback = function ($ch, $str) {
global $result;
//$str has the chunks of data streamed back.
$result .= $str;
// here you can mess with the stream data either with $result or $str.
// i.e. look for the "Job waiting" string and terminate the response.
return strlen($str);//don't touch this
};
$url = "partial_response.php";
$sac_curl = curl_init();
curl_setopt($sac_curl, CURLOPT_HTTPGET, true);
curl_setopt($sac_curl, CURLOPT_URL, $url);
curl_setopt($sac_curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($sac_curl, CURLOPT_HEADER, false);
curl_setopt($sac_curl, CURLOPT_TIMEOUT, 11);
curl_setopt($ch, CURLOPT_WRITEFUNCTION, $callback);
curl_exec($sac_curl); // the response is now in $result.
curl_close($sac_curl);
echo $result;