URL不能以字符结尾吗？

Question

What characters (if any) can a web browser URL (http/https) not end with?

As far as I can tell, control characters aren't used eg

• \\0 nil.
• \\t tab.
• \\n newline.
• space (from testing seems this is stripped).

Is there a complete list of such characters?

Answer 1

There are three cases how a URI can end:

• with the path component (if it has no query/fragment)

   http://example.com/ http://example.com/path http://example.com/path/path 

• with the query component (if it has no fragment)

   http://example.com/?query http://example.com/path?query http://example.com/path/path?query 

• with the fragment component

   http://example.com/#fragment http://example.com/path#fragment http://example.com/path/path#fragment http://example.com/?query#fragment http://example.com/path?query#fragment http://example.com/path/path?query#fragment 

The URI standard doesn't place any restrictions on the end of these three components ( Path , Query , Fragment ), so the same characters are allowed that can appear anywhere else in the components:

• characters allowed in the path component
• characters allowed in the query component
• characters allowed in the fragment component

space (from testing seems this is stripped)

URIs can have (multiple) space characters at the end (in all three cases), but they have to be percent-encoded. Spaces aren't allowed unencoded, no matter where.

http://example.com/path-ending-with-four-spaces-%20%20%20%20

If a user agent tries to convert user input into a valid URI (ie, percent-encoding all characters that can't appear in the component), it might assume that trailing spaces aren't intended to be part of the URI, and strip them.

The same goes for tab and newline characters. They can be part of URIs if percent-encoded.