Is possible to establish a connection between a browser and a CMD/PowerShell process at browser launch?

1

I have been looking for a means of running external script/programs against events on a web page in a browser such as “On button Click” or “On Page change”.

I am able to easily do this with the Dev Tools found in browsers. For example, in the console, I can override the default behaviour of myImage with this:

myImage.onclick = function() {
	alert('Hello World')
}

This is exactly what I need, but I have since then learnt that its ‘officially’ not possible to run scripts/programs belonging to the host machine. This seems to a be core security feature of JavaScript/Web browsers.

I am now looking for alternative means of doing the above

Is it possible to start a ‘browsing session’ at the terminal, something like ‘test mode’ or ‘debugging mode’, so that it is connected to the shell that launched it, this way I can write my code in the Dev Tools console:

myImage.onclick = function() {
	logTerminal('Button has been clicked!')     //possibly a custom function
}

and when the event triggers, the browser outputs a message to the terminal its connected to, Button has been clicked!. and I am free to respond to it at the terminal.

Searching around, I came across Selenium but its feature set seems to be limited (I may be wrong) compared to what I can do at the Dev Tools console. Selenium seems to be based on polling, where the Dev Tools are event driven. I am looking for an event driven solution.

Note: I am NOT looking to deploy this as a solution for a live website, I am merely looking to, only on my local machine, “hook” into user events, like click, on sites such as the BBC/Nasa, so I can efficiently run my own tools at the right time, rather relying on polling.

Any help would be greatly appreciated!

2

Please explain your actual goal. What is it you are trying to do exactly?

I’m talking about the exact functionality needed, not theoretical.

3

Yes, this a core security feature, you absolutely cannot do this directly.

The normal way to do something similar to what you appear to want is to run a server, then use the HTTP APIs in the browser to send messages to/from that server.

This isn’t trivial to do from scratch, particularly if you have little experience.

Something like Selenium is doing the opposite to what I think you want: it is just using the browser JS API to control web page interactions.

As @lasjorg says, would help to know exactly what you want to do (I think it is possible that using a browser is not actually what you want)

1 Like
4

You are mixing local and remote here.

We really need to know what it is you are trying to do to give a proper answer.

  • A browser extension can interact with websites and add functionality. It should be possible to use it in concert with native applications but I don’t know enough about it (extension docs nativeMessaging).

  • Something like Selenium/Puppeteer/Playwright lets you interact with websites and perform actions based on conditions. They are mostly used for web scraping and site testing but it is possible to run external commands/applications as well.

  • A NodeJS server can respond to API calls from clients, run commands on the server, and send back a response to the clients.

  • NodeJS using something like Electron lets you create desktop applications written in JS.

5

That “Native Messaging” was exactly what I need and more. Using MDN extension example (hosted on Github) I was able to reproduce my own version.

Its really clever, using stdout and stdin I can even communicate back to the browser/extension.

Amazing. Thank you.

6

I was just looking for a solution that is akin to windows “shell hook” system but for the web browser/pages.
So, that like in Windows, if some event I subscribed to happens (on a webpage), my program will be informed and I can call my own function to do something that I want.

So far all the solutions I could manage was “polling” I needed an “event” based solution, which I found here. Cheers.

7

Great, good to hear you found something that works for you.

8

This topic was automatically closed 182 days after the last reply. New replies are no longer allowed.