Is there any software available that lets you know when a website has changed?

I'm looking for a new car on craigslist and i essentially don't want to check each time I want something that will monitor the webpage and when a new posting has been done it immediatley notifies me.Is there any software available that lets you know when a website has changed?You're posting in the Programming section (as opposed to Internet or Software), so I assume you want an answer in terms of a programmer's viewpoint.



Craigslist happens to have RSS feeds, so you could scrape them periodically. Or use a script to download the content. It could take a hash of the content, and when the content changes, the hash changes. Hence, you know when the webpage has changed.
Is there any software available that lets you know when a website has changed?
i have no idea



thank you
Is there any software available that lets you know when a website has changed?
There is a JavaScript command that will tell you when a webpage was modified; you could create a program that runs that javascript command and report to you when the date changes.



how you use it:

1. Load the webpage

2. Type %26quot;javascript:alert(document.lastModified)鈥?into the address bar and click %26quot;go%26quot;

3. Take the last two steps and do them programmatically, and have the program alert you when the result changes