I was wondering if I can upload a file to the web server by passing the file as string of bytes in the URL. I know this is possible for other form elements by using the syntax:
www.example.com\index.php?user="user"&pass="pass"..etc
If it's possible, what is the format of the byte string?
In theory, sure. HTML forms allowing file uploads usually make a browser perform a POST query. (See here for some details.) Servers usually don't care how that query was created on the client side. (If they want to care, they must implement cross-site request forgery prevention measures.)
Thus in practice, this depends on your client: If it can construct the POST request without the form, you're set.
POST requests?In theory, yes, if they aren't too large. (URLs are limited in length.) Nothing in the HTTP protocol forbids you to do that.
In practice, there is probably no established convention on how to do this, so your client and your server will have to feature some custom implementation for this and to agree on the encoding etc.
Thus you can decide the format of the encoded string (as long as it's allowed within an URL parameter), but you would probably also have to implement that format on either side.
