PHP loop curl request one by one - php

Question

How to make a foreach or a for loop to run only when the curl response is received..
as example :
for ($i = 1; $i <= 10; $i++) {
$ch = curl_init();
curl_setopt($ch,CURLOPT_URL,"http://www.example.com");
if(curl_exec($ch)){ // ?? - if request and data are completely received
// ?? - go to the next loop
}
// DONT go to the next loop until the above data is complete or returns true
}
i don't want it to move to the next loop without having the current curl request data received.. one by one, so basically it opens up the url at first time, waits for the request data, if something matched or came true then go to the next loop,
you dont have to be bothered about the 'curl' part, i just want the loop to move one by one ( giving it a specific condition or something ) and not all at once

Answer 1

The loop ought to already work that way, for you're using the blocking cURL interface and not the cURL Multi interface.
$ch = curl_init();
for ($i = 1; $i <= 10; $i++)
{
curl_setopt($ch, CURLOPT_URL, "http://www.example.com");
$res = curl_exec($ch);
// Code checking $res is not false, or, if you returned the page
// into $res, code to check $res is as expected
// If you're here, cURL call completed. To know if successfully or not,
// check $res or the cURL error status.
// Removing the examples below, this code will hit always the same site
// ten times, one after the other.
// Example
if (something is wrong, e.g. False === $res)
continue; // Continue with the next iteration
Here extra code to be executed if call was *successful*
// A different example
if (something is wrong)
break; // exit the loop immediately, aborting the next iterations
sleep(1); // Wait 1 second before retrying
}
curl_close($ch);

Answer 2

Your code (as is) will not move to the next iteration until the curl call is completed.
A couple of issues to consider
You could set a higher timeout for curl to ensure that there are no communication delays. CURLOPT_CONNECTTIMEOUT, CURLOPT_CONNECTTIMEOUT_MS (milliseconds), CURLOPT_DNS_CACHE_TIMEOUT, CURLOPT_TIMEOUT and CURLOPT_TIMEOUT_MS (milliseconds) can be used to increase the timeouts. 0 makes curl wait indefinitely for any of these timeouts.
If your curl request fails for whatever reason, you can just put an exit there to stop execution, This way it will not move to the next URL.
If you want the script to continue even after the first failure, you can just log the result (after the failed request) and let it continue in the loop. Examining the log file will give you information as to what happened.

Answer 3

The continue control structure should be what you are looking for:
continue is used within looping structures to skip the rest of the current loop iteration and continue execution at the condition evaluation and then the beginning of the next iteration.
http://php.net/manual/en/control-structures.continue.php
for ($i = 1; $i <= 10; $i++) {
$ch = curl_init();
curl_setopt($ch,CURLOPT_URL,"http://www.example.com");
if(curl_exec($ch)){ // ?? - if request and data are completely received
continue; // ?? - go to the next loop
}
// DONT go to the next loop until the above data is complete or returns true
}

Answer 4

You can break out of a loop with the break keyword:
foreach ($list as $thing) {
if ($success) {
// ...
} else {
break;
}
}

Answer 5

for($i = 1; $i <= 10; $i++) {
$ch = curl_init();
curl_setopt($ch,CURLOPT_URL,"http://www.example.com");
if(curl_exec($ch)){ // ?? - if request and data are completely received
continue;
}else{
break;
}
// DONT go to the next loop until the above data is complete or returns true
}
or
for($i = 1; $i <= 10; $i++) {
$ch = curl_init();
curl_setopt($ch,CURLOPT_URL,"http://www.example.com");
if(curl_exec($ch)===false){ // ?? - if request and data are completely received
break;
}
}