How to Effectively Handle 404 Errors During Web Scraping in PHP?

How to Efficiently Handle 404 Errors in PHP

When scraping web pages, encountering 404 (Not Found) errors can disrupt your code flow. To avoid such interruptions, it's essential to implement robust URL validation at the outset.

fsockopen Method Limitations

The blog's suggestion to use fsockopen() has limitations, particularly when dealing with redirects. It may return an empty $valid value even for valid URLs.

Introducing curl and curl_getinfo()

PHP's curl library provides an alternative approach that effectively handles redirects and returnsの詳細なHTTP情報を提供します。 With curl_getinfo(), you can retrieve the HTTP status code after executing a cURL request. Here's a sample code using curl to check for 404 errors:

$handle = curl_init($url);
curl_setopt($handle,  CURLOPT_RETURNTRANSFER, TRUE);

/* Get the HTML or whatever is linked in $url. */
$response = curl_exec($handle);

/* Check for 404 (file not found). */
$httpCode = curl_getinfo($handle, CURLINFO_HTTP_CODE);
if($httpCode == 404) {
    /* Handle 404 here. */
}

curl_close($handle);

/* Handle $response here. */

In this code:

• A cURL session is initialized using curl_init().
• curl_setopt() configures the session to return a $response string.
• curl_exec() executes the request.
• curl_getinfo() retrieves the HTTP status code ($httpCode).
• If $httpCode is 404, the code handles the error.

By utilizing this method, you can efficiently handle 404 errors and ensure your scraping code runs smoothly.

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