1. base64_encode - Encoding data using MIME base64
In order to enable binary data to be transmitted through a non-pure 8-bit transport layer, such as the main body of e-mail.
Base64 requires that every three 8Bit bytes be converted to four 6Bit bytes (3*8 = 4*6 = 24), and then add two higher bits of 0 to the 6Bit to make up four 8Bit bytes, that is to say, the converted string will theoretically be one third longer than the original one.
Base64-encoded data takes up about 33% more space than the original data.
The encrypted string format is: upper and lower case letters, numbers, "+" number, "=" number and "/" number, and "=" number up to two.
base64 encoding url problem (reference):
//URL base 64 coding function urlsafe_b64encode($string) { $data = base64_encode($string); $data = str_replace(array('+','/','='),array('-','_',''),$data); return $data; } //URL base 64 decoding function urlsafe_b64decode($string) { $data = str_replace(array('-','_'),array('+','/'),$string); $mod4 = strlen($data) % 4; if ($mod4) { $data .= substr('====', $mod4); } return base64_decode($data); }
2. base64_decode - Decoding data using MIME base64 encoding
3. rawurlencode - Code URL s according to RFC 3986
Before PHP 5.3.0, rawurlencode coded wavy lines (~) based on RFC 1738.
All non-alphanumeric characters except - in the string will be replaced by a percentage sign (%) followed by two hexadecimal digits.
4. rawurldecode - Decoding encoded URL strings
The sequence of percentiles (%) followed by two hexadecimal digits in the string will be replaced by the original character.
5. urlencode - encoding URL strings
All non-alphanumeric characters except - in this string will be replaced by a percent sign (%) followed by two hexadecimal digits, and spaces will be encoded by a plus sign (+). This encoding is the same as that of WWW form POST data, and the same as that of application/x-www-form-urlencoded media type encoding. For historical reasons, this encoding is compared with RFC3896 encoding in encoding spaces as plus sign (+).
6. urldecode - Decode encoded URL strings
Decode any% of the encoded string given. The plus sign ('+') is decoded into a space character.
Example:
$str = 'xia22wd'; $str2 = 'aHFZONlN2gkONRbUKCcM5y9Y+e2UbXK70JurgX3XcSU='; //base64_encode, Base64 decode encryption and decryption $base_enstr = base64_encode($str); $base_destr = base64_decode($base_enstr); //urlencode, urldecode conversion string $urlen_str = urlencode($str2); $urlde_str = urldecode($str2); //rawurlencode, rawurldecode conversion strings $rawurlen_str = rawurlencode($str2); $rawurlde_str = rawurldecode($str2); //Output the execution results of each function echo '<b>str</b>: '.$str.'<br>'; echo '<b>base64_encode</b>: '.$base_enstr.'<br>'; echo '<b>base64_decode</b>: '.$base_destr.'<br>'; echo '<b>urlencode</b>: '.$urlen_str.'<br>'; echo '<b>urldecode</b>: '.$urlde_str.'<br>'; echo '<b>rawurlencode</b>: '.$rawurlen_str.'<br>'; echo '<b>rawurldecode</b>: '.$rawurlde_str.'<br>';
The result is:
str: xia22wd base64_encode: eGlhMjJ3ZA== base64_decode: xia22wd urlencode: aHFZONlN2gkONRbUKCcM5y9Y%2Be2UbXK70JurgX3XcSU%3D urldecode: aHFZONlN2gkONRbUKCcM5y9Y e2UbXK70JurgX3XcSU= rawurlencode: aHFZONlN2gkONRbUKCcM5y9Y%2Be2UbXK70JurgX3XcSU%3D rawurldecode: aHFZONlN2gkONRbUKCcM5y9Y+e2UbXK70JurgX3XcSU=