http://example.com/file, the path section of the URL gets extracted and is turned into
/filein the HTTP request line. That item in the protocol is called the request target in HTTP. That is the resource this request will interact with. Normally this request target is extracted from the URL and then used in the request and as a user you do not need to think about it.
*for that. Yes, a single asterisk. There is no way to specify a URL for this, so if you want to pass a single asterisk in the request target to a server, like for OPTIONS, you have to do it like this:
/./in the path, curl will automatically squash them before the path is sent to the server, as is dictated by standards and how such strings tend to work in local file systems. The
/../sequence will remove the previous section so that
/hello/sir/../ends up just
/./is simply removed so that