kenlistian

方法一：

def URLDecode(str)
str.gsub!(/%[a-fA-F0-9]{2}/) { |x| x = x[1..2].hex.chr }
end

def URLEncode(str)
str.gsub!(/[^\w$&\-+.,\/:;=?@]/) { |x| x = format("%%%x", x[0]) }
end

链接：http://www.2maomao.com/blog/2-ruby-cookies-en-de-code/

方法二：

采用ERB::Util.url_encode()

其中在url_encode 处理如下

def url_encode(s)
s.to_s.gsub(/[^a-zA-Z0-9_\-.]/n){ sprintf("%%%02X", $&.unpack("C")[0]) }
end

在正则表达式中：

[^a-zA-Z0-9_\-.]表示匹配非a-z 和A-Z 包括0-9 以及下划线和-中横线 的字符，

$& 全局变量，匹配到的字符串存放在 $& 变量中

uppack 是字符对象中的一个方法：是拆字符到数组的函数，

str.unpack( format ) -> anArray

Decodes str (which may contain binary data) according to the format string,

returning an array of each value extracted. 。。

其中C表示按字符拆。还有参数如下：

Directives for String#unpack

Format Function Returns

A String with trailing nulls and spaces removed. String

a String. String

B Extract bits from each character (msb first). String

b Extract bits from each character (lsb first). String

C Extract a character as an unsigned integer. Fixnum

c Extract a character as an integer. Fixnum

d Treat sizeof(double) characters as a native double. Float

E Treat sizeof(double) characters as a double in little-endian byte order. Float

e Treat sizeof(float) characters as a float in little-endian byte order. Float

f Treat sizeof(float) characters as a native float. Float

G Treat sizeof(double) characters as a double in network byte order. Float

g Treat sizeof(float) characters as a float in network byte order. Float

H Extract hex nibbles from each character (most significant first). String

h Extract hex nibbles from each character (least significant first). String

I Treat sizeof(int) ¹ successive characters as an unsigned native integer. Integer

i Treat sizeof(int) ¹ successive characters as a signed native integer. Integer

L Treat four¹ successive characters as an unsigned native long integer. Integer

l Treat four¹ successive characters as a signed native long integer. Integer

M Extract a quoted-printable string. String

m Extract a base64 encoded string. String 能把base64直接解出。

N Treat four characters as an unsigned long in network byte order. Fixnum

n Treat two characters as an unsigned short in network byte order. Fixnum

P Treat sizeof(char *) characters as a pointer, and return len characters from the referenced location. String

p Treat sizeof(char *) characters as a pointer to a null-terminated string. String

S Treat two¹ successive characters as an unsigned short in native byte order. Fixnum

s Treat two¹ successive characters as a signed short in native byte order. Fixnum

U Extract UTF-8 characters as unsigned integers. Integer

u Extract a UU-encoded string. String

V Treat four characters as an unsigned long in little-endian byte order. Fixnum

v Treat two characters as an unsigned short in little-endian byte order. Fixnum

X Skip backward one character. ---

x Skip forward one character. ---

Z String with trailing nulls removed. String

@ Skip to the offset given by the length argument.

其中参数带个上述格式，还可在格式后跟个数字or*，表示做几次拆解，

我靠，日本人搞的东西咋这么复杂呢，以为是unix啊，@#￥%！@#￥！，慢慢看吧。

自我感觉比c难学。不过他这一步就可以做好多事情，很好很强大啊。