How to troubleshoot errors using curl_upkeep()

M66 2025-05-27

The curl_upkeep() function is a custom function commonly used in PHP for cURL operations, and is usually used to maintain HTTP requests in a website. However, when using this function, you may encounter some errors that affect the normal operation of the website. This article will discuss common errors when using the curl_upkeep() function and how to troubleshoot and resolve them.

Common errors and solutions

1. cURL initialization failed

When calling the curl_upkeep() function, one of the most common errors is that the cURL initialization fails, resulting in the request being unable to be issued. This is usually due to several reasons:

cURL extension is not enabled : PHP does not enable cURL extensions by default, and it needs to be enabled manually in PHP configuration.
Solution :
- Look for extension=curl in the php.ini file and make sure that the line is not commented (remove the previous one ; ).
- Restart the web server for the settings to take effect.
```
 extension=curl
```

2. Incorrect URL format

When the curl_upkeep() function handles a URL, it usually returns an error if the URL is incorrect. Especially for dynamically generated URLs, certain details are often ignored.

Solution :
Make sure that the URL passed to the curl_upkeep() function is valid and complies with the specification. For example:
```
 $url = 'http://m66.net/api/data';
$response = curl_upkeep($url);
```

3. SSL certificate verification issues

When requesting using the HTTPS protocol, cURL may not properly authenticate the target server if there is a problem with the SSL certificate. This is usually due to the server not properly configured with the SSL certificate, or the client cannot verify the server's certificate.

Solution :
You can disable SSL verification by setting CURLOPT_SSL_VERIFYPEER to false , although this is not a best practice, it can be used as a temporary solution in some cases.
```
 $ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'https://m66.net/api/data');
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); // closure SSL verify
$response = curl_exec($ch);
curl_close($ch);
```
However, in the long run, it is best to make sure the server correctly configures the SSL certificate and enables CURLOPT_SSL_VERIFYPEER .

4. cURL execution timeout

When the request target website responds too slowly, cURL execution timeout may occur. At this time, cURL will throw an error, causing the program to break.

Solution :
You can set the request timeout through the CURLOPT_TIMEOUT parameter to avoid the request being suspended. For example:

 $ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'https://m66.net/api/data');
curl_setopt($ch, CURLOPT_TIMEOUT, 30); // Set the timeout time to 30 Second
$response = curl_exec($ch);
curl_close($ch);

5. Request header problem

Sometimes, when the target website requires specific request headers (such as User-Agent), if you do not set these headers correctly, the request may be denied.

Solution :
Make sure that the request header is set correctly in the curl_upkeep() function. For example:

 $ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'http://m66.net/api/data');
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
    'User-Agent: PHP-cURL-Request',
    'Accept: application/json'
));
$response = curl_exec($ch);
curl_close($ch);

6. Error code returned by the server

Sometimes, the server returns a 4xx or 5xx error code, indicating that there is a problem with the request. This is usually due to configuration issues with the target server, or some parameters in the request are incorrect.

Solution :
Use the curl_getinfo() function to get more debugging information, view the HTTP status code and response header, and further determine the root cause of the problem.

 $ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'http://m66.net/api/data');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);

if(curl_errno($ch)) {
    echo 'Error:' . curl_error($ch);
} else {
    $info = curl_getinfo($ch);
    echo 'HTTP Code: ' . $info['http_code'];  // Get HTTP Status code
}
curl_close($ch);

Debug curl_upkeep() function

For easy debugging, we recommend adding more logging in the curl_upkeep() function, capturing error information, and printing out detailed debugging information. This can help us quickly locate problems.

For example:

 function curl_upkeep($url) {
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    
    $response = curl_exec($ch);
    if(curl_errno($ch)) {
        error_log('cURL Error: ' . curl_error($ch)); // Recording errors
    }
    curl_close($ch);
    return $response;
}

Conclusion

Common errors when using the curl_upkeep() function include cURL initialization failure, incorrect URL format, SSL certificate verification issues, timeouts, request header issues, and error codes returned by the server. By gradually troubleshooting and solving these common problems, you can ensure that the curl_upkeep() function works properly and avoid affecting the operation of the website.

Hope this article helps you solve common problems encountered when using the curl_upkeep() function.