Hi everybody =) My name is Javier and I'm from Argentina.
I've had a little issue with latin characters like ñ","Ñ","á","é","í", etc.
They are not decoded with rawurlencode(), so I've made this:
<?php
function urlRawDecode($raw_url_encoded)
{
$hex_table = array(
0 => 0x00,
1 => 0x01,
2 => 0x02,
3 => 0x03,
4 => 0x04,
5 => 0x05,
6 => 0x06,
7 => 0x07,
8 => 0x08,
9 => 0x09,
"A"=> 0x0a,
"B"=> 0x0b,
"C"=> 0x0c,
"D"=> 0x0d,
"E"=> 0x0e,
"F"=> 0x0f
);
if(preg_match_all("/\%C3\%([A-Z0-9]{2})/i", $raw_url_encoded,$res))
{
$res = array_unique($res = $res[1]);
$arr_unicoded = array();
foreach($res as $key => $value){
$arr_unicoded[] = chr(
(0xc0 | ($hex_table[substr($value,0,1)]<<4))
| (0x03 & $hex_table[substr($value,1,1)])
);
$res[$key] = "%C3%" . $value;
}
$raw_url_encoded = str_replace(
$res,
$arr_unicoded,
$raw_url_encoded
);
}
return rawurldecode($raw_url_encoded);
}
print urlRawDecode("%C3%A1%C3%B1");
?>
For example, you have the character "ñ" encoded like this "%C3%B1".
This is nothing more and nothing less than 0xc3 and 0xb1,
they are binary numbers, (HHHH LLLL, where HHHH=High and LLLL=Low).
0xc3 = 1100 0011 (binary 8 bit word), 0xb1 = 1011 0001 (binary 8 bit word),
To convert a raw encoded character to ascii we have to make boolean operations
between this two operands (0xc3 and 0xb1), boolean algebra were defined by George
Boole, we need to use them here. The first one we going to use is the
logical OR ("|" or "pipe") and logical AND ("&" or "and person").
A logical OR implies the following truth table:
a b (a OR b)
0 0 0
0 1 1 (a OR b or Both, a and b, must be true to get a true result)
1 0 1
1 1 1
A logical AND implies the following truth table:
a b (a AND b)
0 0 0
0 1 0
1 0 0
1 1 1 (Both a AND b, must be true to get a true result)
So, here we have to make a logical OR with both 0xc3 and 0xb1 HIGH nibble,
a nibble is a half byte (4 bits), so we have to make a logical OR between
1100 (0xc) and 1011 (0xb), we going to get this: 1111 (0xf), then we have to make
a logical AND between both LOW nibble, 0011 (0x3) and 0001 (0x1), we going to get
this: 0001, so, if we want to see the final result, we have to put HIGH and LOW
nibble on his Byte position, like this: 1111 0001 (0xf1) and that is nothing
more and nothing less than "ñ" (to check this out, try the following: print(chr(0xf1));).
This "<<" is a logical shift left, if we have this binary number 0001 (1) and we make this:
0001 << 2 we'll get 0100 (4) right bits are filled with 0's.
<?php
print(
chr(
(0xc0|0x0b<<4) | (0x03&0x01)
)
);
?>
PS: I'm so sorry about my english, I know, is horrible :P