For example, compress the php bcd code-compress the decimal number to the hexadecimal data.
| The code is as follows: |
Copy code |
<? Php
/*
Php bcd code compression-compress decimal numbers into hexadecimal data
For example, 0x00 0x91 after 0091 compression
*/
$ String = '000000 ';
$ Bytes = Bytes: getBytes ($ string );
Print_r ($ bytes );
/*
Array
(
[0] => 48
[1] => 48
[2] => 57
[3] => 49
)
*/
$ Asc = Bytes: AscToHex ($ bytes, 4 );
// 4-bit compression into 2-bit
Print_r ($ asc );
/*
Array
(
[0] => 0
[1] => 145.
)
*/
Echo Bytes: toStr ($ asc );
/*
0091
*/
$ Hex = Bytes: HexToAsc ($ asc, 2 );
// Reverse operation 2-bit to 4-bit
Print_r ($ hex );
/*
Array
(
[0] => 48
[1] => 48
[2] => 57
[3] => 49
)
*/
?> |
For example, compress the decimal number into the hexadecimal data.
| The code is as follows: |
Copy code |
<? Php
/**
* Php bcd code compression
* Compress the decimal number to the hexadecimal data.
* @ Author phpff.com
* Created on 2011-7-15
*/
Class Bytes {
/**
* Convert a String to a byte array.
* @ Param $ str the string to be converted
* @ Param $ bytes target byte array
* @ Author phpff.com
*/
Public static function getBytes ($ string ){
$ Bytes = array ();
For ($ I = 0; $ I <strlen ($ string); $ I ++ ){
$ Bytes [] = ord ($ string [$ I]);
}
Return $ bytes;
}
/**
* Convert byte arrays to String-type data.
* @ Param $ bytes byte array
* @ Param $ str target string
* @ Return a String type data
*/
Public static function toStr ($ bytes ){
$ Str = '';
Foreach ($ bytes as $ ch ){
$ Str. = bin2hex (chr ($ ch ));
}
Return $ str;
}
/**
* Convert asc code to hexadecimal data
* @ Param $ asc numeric string
* @ Param $ AscLen the length of the string to be converted
* @ Return hexadecimal array
* @ Author phpff.com
*/
Public static function AscToHex ($ asc, $ AscLen ){
$ I = 0;
$ Hex = array ();
For ($ I = 0; 2 * $ I <$ AscLen; $ I ++)
{
/* A: 0x41 (0100 0001), a: 0x61 (0110 0001), 0001 after four digits shifted to the right, and 0 XA such as 0x90 */
$ Hex [$ I] = (chr ($ asc [2 * $ I]) <4 );
If (! (Chr ($ asc [2 * $ I])> = '0' & chr ($ asc [2 * $ I]) <= '9 ')){
$ Hex [$ I] + = 0x90;
}
If (2 * $ I + 1 >=$ AscLen ){
Break;
}
$ Hex [$ I] | = (chr ($ asc [2 * $ I + 1]) & 0x0f );
If (! (Chr ($ asc [2 * $ I + 1])> = '0' & chr ($ asc [2 * $ I + 1]) <= '9 ')){
$ Hex [$ I] + = 0x09;
}
}
Return $ Hex;
}
/**
* Convert hexadecimal data to asc code
* @ Param $ Hex hexadecimal array
* @ Param $ HexLen hexadecimal array length
* @ Return asc array
* @ Author phpff.com
*/
Public static function HexToAsc ($ Hex, $ HexLen ){
$ I = 0;
$ Temp = 0;
For ($ I = 0; $ I <$ HexLen; $ I ++)
{
$ Temp = ($ Hex [$ I] & 0xf0)> 4;
If ($ Temp <10 ){
$ Asc [2 * $ I] = (0x30 + $ Temp );
} Else {
$ Asc [2 * $ I] = (0x37 + $ Temp );
}
$ Temp = $ Hex [$ I] & 0x0f;
If ($ Temp <10 ){
$ Asc [2 * $ I + 1] = (0x30 + $ Temp );
} Else {
$ Asc [2 * $ I + 1] = (0x37 + $ Temp );
}
}
Return $ Asc;
}
}
?> |
