How to browse a web page periodically and check for certain sting

alilet

I want to monitor a web page or multiple ones for a certain keyword present in HTML. Actually I am doing this for a friend as she wants to order one item from a clothing website and it remains out of stock most of the time.
So, I want to make her a service/cron job that will monitor if the stock is available and send her alert.
I know I can do this in PHP using file_get_contents but I was thinking if there is a better way to do it as the site may ban me if I check it very often and I think it cannot emulate browser very good. Or may be we can emulate browser using file_get_contents.
Suggest me some better way. May be some browser library I can use in PHP that will open that page and read HTML?

EthernetServers

Nodeping has this functionality, if you're willing to pay: https://nodeping.com/http_content_check.html

Or you can just check out that link to learn more about how it works, and then build your own version.

cpsd

Hi ! I am using this opensource project that you can selfhost

https://github.com/dgtlmoon/changedetection.io

alilet

I went ahead and wrote the following very simple script. It checks for certain string in web page and is running fine for the past 3 days. As soon as that string is found, it will send WhatsApp message to her.

This is not complete code but just initial part of it which calls web page.

$url = "https://www.example.com";

$context = stream_context_create(
        array(
            "http" => array(
                'method'=>"GET",
                "header" => "User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) 
                            AppleWebKit/537.36 (KHTML, like Gecko) 
                            Chrome/50.0.2661.102 Safari/537.36\r\n" .
                            "accept: text/html,application/xhtml+xml,application/xml;q=0.9,
                            image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3\r\n" .
                            "accept-language: es-US,us;q=0.9,en;q=0.8,it;q=0.7\r\n"
            )
        )
    );

$f = file_get_contents($url, false, $context);

gwnd1989

Ask chatgpt

instavps

I use visual ping free version, seems to work.