If I have a URL:
http://mysite.com/part1/page.aspx
What is the name of the part1 part in that URL?
Justin is correct - it's one part of the path. Adding a reference to the URI RFC, for the pretty picture contained therein, which illustrates (in section 3) each part of an example URI:
foo://example.com:8042/over/there?name=ferret#nose
\_/ \______________/\_________/ \_________/ \__/
| | | | |
scheme authority path query fragment
Further on, in the section devoted to the path:
A path consists of a sequence of path segments separated by a slash
("/") character. A path is always defined for a URI, though the
defined path may be empty (zero length). Use of the slash character
to indicate hierarchy is only required when a URI will be used as the
context for relative references. For example, the URI
mailto:fred#example.com has a path of "fred#example.com", whereas
the URI foo://info.example.com?fred has an empty path. (emphasis mine)
And so "path segment" might be the term you're looking for.
That would be the first part of the path. There's no term to describe that part alone.
I might possibly be name "the protocol"?
Related
A URI is composed of several parts: scheme:[//[user[:password]#]host[:port]][/path][?query][#fragment]. Often, I find myself wanting to refer to the entire part of the URI to the right of the host and port - the part that would be considered the URI in an HTTP request:
GET /path?query#fragment
Host: example.com
As a short-hand, I normally call this the "path", but that's not quite accurate, as the path is only part of it. This is essentially the inverse of What do you call the entire first part of a URL?
Is there an agreed-upon name for this?
Within a full HTTP URI, there doesn’t seem to be a term that denotes everything coming after the authority.
If you only have the part in question as a URI reference (e.g., in a HTTP GET request), it’s called a relative reference:
relative-ref = relative-part [ "?" query ] [ "#" fragment ]
But this term also includes network-path references (often called protocol-relative URIs), e.g. //example.com/path?query#fragment. To exclude this case, you could use the terms for the other two cases:
absolute-path reference (begins with a single /, e.g. /path?query#fragment)
relative-path reference (doesn’t begin with a /, e.g., path?query#fragment)¹
¹ If the first path segment contains a :, you have to begin the relative-path reference with ./ (e.g., ./pa:th?query#fragment).
RFC 7230 says:
request-line = method SP request-target SP HTTP-version CRLF
I personally prefer to use the terms
origin for scheme and authority (where) and
resource for path, query string and fragment (what).
I'm not aware of any term for that portion of a URI.
RFC3986 says this
foo://example.com:8042/over/there?name=ferret#nose
\_/ \______________/\_________/ \_________/ \__/
| | | | |
scheme authority path query fragment
| _____________________|__
/ \ / \
urn:example:animal:ferret:nose
I know absolute path-only URLs (/path/to/resource) are valid, and refer to the same scheme, host, port, etc. as the current resource. Is the URL still valid if the same (or a different!) scheme is added? (http:/path/to/resource or https:/path/to/resource)
If it is valid according to the letter of the spec, how well do browsers handle it? How well do developers that may come across the code in the future handle it?
Addendum:
Here's a simple test case I set up on an Apache server:
resource/number/one/index.html:
link
resource/number/two/index.html:
two
Testing in Chrome 43 on OS X: The URL displayed when hovering over the link looks correct. Clicking the link works as expected. Looking at the DOM in the web inspector, hovering over the a href URL displays an incorrect location (/resource/number/one/http:/resource/number/two/).
Firefox 38 appears to also handle the click correctly. Weird.
No, it’s not valid. From RFC 3986:
4.2. Relative Reference
A relative reference takes advantage of the hierarchical syntax
(Section 1.2.3) to express a URI reference relative to the name space
of another hierarchical URI.
relative-ref = relative-part [ "?" query ] [ "#" fragment ]
relative-part = "//" authority path-abempty
/ path-absolute
/ path-noscheme
/ path-empty
The URI referred to by a relative reference, also known as the target
URI, is obtained by applying the reference resolution algorithm of
Section 5.
A relative reference that begins with two slash characters is termed
a network-path reference; such references are rarely used. A
relative reference that begins with a single slash character is
termed an absolute-path reference. A relative reference that does
not begin with a slash character is termed a relative-path reference.
A path segment that contains a colon character (e.g., "this:that")
cannot be used as the first segment of a relative-path reference, as
it would be mistaken for a scheme name. Such a segment must be
preceded by a dot-segment (e.g., "./this:that") to make a relative-
path reference.
where path-noscheme is specifically a path that doesn’t start with / whose first segment does not contain a colon, which addresses your question pretty specifically.
I have a question regarding URLs:
I've read the RFC 3986 and still have a question about one URL:
If a URI contains an authority component, then the path component
must either be empty or begin with a slash ("/") character. If a URI
does not contain an authority component, then the path cannot begin
with two slash characters ("//"). In addition, a URI reference
(Section 4.1) may be a relative-path reference, in which case the
first path segment cannot contain a colon (":") character. The ABNF
requires five separate rules to disambiguate these cases, only one of
which will match the path substring within a given URI reference. We
use the generic term "path component" to describe the URI substring
matched by the parser to one of these rules.
I know, that //server.com:80/path/info is valid (it is a schema relative URL)
I also know that http://server.com:80/path//info is valid.
But I am not sure whether the following one is valid:
http://server.com:80//path/info
The problem behind my question is, that a cookie is not sent to http://server.com:80//path/info, when created by the URI http://server.com:80/path/info with restriction to /path
See url with multiple forward slashes, does it break anything?, Are there any downsides to using double-slashes in URLs?, What does the double slash mean in URLs? and RFC 3986 - Uniform Resource Identifier (URI): Generic Syntax.
Consensus: browsers will do the request as-is, they will not alter the request. The / character is the path separator, but as path segments are defined as:
path-abempty = *( "/" segment )
segment = *pchar
Means the slash after http://example.com/ can directly be followed by another slash, ad infinitum. Servers might ignore it, but browsers don't, as you have figured out.
The phrase:
If a URI does not contain an authority component, then the path cannot begin
with two slash characters ("//").
Allows for protocol-relative URLs, but specifically states in that case no authority (server.com:80 in your example) may be present.
So: yes, it is valid, no, don't use it.
According to RFC 3986 Section 3 - Syntax Components:
The scheme and path components are required, though the path may be
empty (no characters).
Can someone clarify how the path component can be required if it's able to be empty? Maybe I'm misunderstanding the definition of "required" in this context, but I assumed it to mean something along the lines of "must be non-empty," which obviously conflicts with the spec here.
Here, "required" means merely "always present": the scheme and path
components of an absolute URI are always present.
The scheme component can't be empty because the production
"scheme" requires at least one character.
The path component can be empty because the production
"path-empty" (part of "hier-part") consists of zero characters.
A common practical example of an empty - more precisely, an abempty - path is a URI like http://stackoverflow.com where the path is empty. The authority component (in this case it is stackoverflow.com) alone isn't enough information to identify a resource.
When the authority is empty, the path must begin with a / in order to distinguish the path from the authority - scheme:/// is a valid URI - hence an abempty path. Also take a look at this answer for further reading.
I just learned from a colleague that omitting the "http | https" part of a URL in a link will make that URL use whatever scheme the page it's on uses.
So for example, if my page is accessed at http://www.example.com and I have a link (notice the '//' at the front):
Google
That link will go to http://www.google.com.
But if I access the page at https://www.example.com with the same link, it will go to https://www.google.com
I wanted to look online for more information about this, but I'm having trouble thinking of a good search phrase. If I search for "URLs without HTTP" the pages returned are about urls with this form: "www.example.com", which is not what I'm looking for.
Would you call that a schemeless URL? A protocol-less URL?
Does this work in all browsers? I tested it in FF and IE 8 and it worked in both. Is this part of a standard, or should I test more browsers?
Protocol relative URL
You may receive unusual security warnings in some browsers.
See also, Wikipedia Protocol-relative URLs for a brief definition.
At one time, it was recommended; but going forward, it should be avoided.
See also the Stack Overflow question Why use protocol-relative URLs at all?.
It is called network-path reference (the part that is missing is called scheme or protocol) defined in RFC3986 Section 4.2
4.2 Relative Reference
A relative reference takes advantage of the hierarchical syntax
(Section 1.2.3) to express a URI reference relative to the name space
of another hierarchical URI.
relative-ref = relative-part [ "?" query ] [ "#" fragment ]
relative-part = "//" authority path-abempty
/ path-absolute
/ path-noscheme
/ path-empty
The URI referred to by a relative reference, also known as the target URI, is obtained by applying the reference resolution
algorithm of Section 5.
A relative reference that begins with two slash characters is
termed a network-path reference (emphasis mine); such references are rarely used.
A relative reference that begins with a single slash character is termed an absolute-path reference. A relative reference that does not begin with a slash character is termed a relative-path reference.
A path segment that contains a colon character (e.g., "this:that") cannot be used as the first segment of a relative-path reference, as it would be mistaken for a scheme name. Such a segment must be preceded by a dot-segment (e.g., "./this:that") to make a relative- path reference.