重新检查文件以获取更新的内容

Question

I'm trying to recheck a file on a timed interval. I'm not sure if this can be accomplished, but any help would be greatly appreciated. I understand that as PHP is server-sided, it cannot accomplish my task, so anything with JavaScript is fine.

By rechecking a file, I mean getting a file's contents, but only if it's updated. Somewhat like "if file gets new contents, output them."

Answer 1

If you are checking on a remote file, then the PHP solution would be best: simply send the file and its checksum, then when the checksum changes, the file has been updated.

If you're working with a local file, then (if I'm seeing things right) you'll need a browser with the HTML5 File API. May be a duplicate of this: Check if file has changed using HTML5 File API