phpversion()>=5.3 will compliant with RFC 3986, while phpversion()<=5.2.7RC1 is not compliant with RFC 3986.php
參考 RFC3896 方式編碼java
返回字符串,此字符串中除了 -_. 以外的全部非字母數字字符都將被替換成百分號(%)後跟兩位十六進制數,空格則編碼爲加號(+)。
此編碼與 WWW 表單 POST 數據的編碼方式是同樣的,同時與 application/x-www-form-urlencoded 的媒體類型編碼方式同樣。
因爲歷史緣由,此編碼在將空格編碼爲加號(+)方面與 » RFC3896 編碼(參見 rawurlencode())不一樣。
php並無徹底按照 rfc3896編碼,符號【~】在標準中是不用編碼,可是他也編碼了。git
因此最終的未編碼的字符列表爲 [-], [_], [.],如同其文檔中描述的同樣api
參考 RFC2396 方式編碼瀏覽器
可是因爲ie瀏覽器編碼了除 "-", "_", ".", "*" 以外的字符,java採用了和IE同樣的編碼列表,app
因此最終的未編碼的字符列表爲 [-], [_], [.], [*]less
The list of characters that are not encoded has been determined as follows: RFC 2396 states: ----- Data characters that are allowed in a URI but do not have a reserved purpose are called unreserved. These include upper and lower case letters, decimal digits, and a limited set of punctuation marks and symbols. unreserved = alphanum | mark mark = "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")" Unreserved characters can be escaped without changing the semantics of the URI, but this should not be done unless the URI is being used in a context that does not allow the unescaped character to appear. ----- It appears that both Netscape and Internet Explorer escape all special characters from this list with the exception of "-", "_", ".", "*". While it is not clear why they are escaping the other characters, perhaps it is safest to assume that there might be contexts in which the others are unsafe if not escaped. Therefore, we will use the same list. It is also noteworthy that this is consistent with O'Reilly's "HTML: The Definitive Guide" (page 164). As a last note, Intenet Explorer does not encode the "@" character which is clearly not unreserved according to the RFC. We are being consistent with the RFC in this matter, as is Netscape.
RFC 1738 section 2.2
only alphanumerics, the special characters "$-_.+!*'(),", and
reserved characters used for their reserved purposes may be used
unencoded within a URL.ide
RFC 2396 section 2.3
unreserved = alphanum | mark
mark = "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")"ui
RFC 2732 section 3
(3) Add "[" and "]" to the set of 'reserved' characters:this
RFC 3986 section 2.3
unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"
RFC 3987 section 2.2
unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"