hex2bin
(PHP >= 5.4.0)
hex2bin — Decodes a hexadecimally encoded binary string
Description
string hex2bin
( string
$data
)Decodes a hexadecimally encoded binary string.
Caution
This function does NOT convert a hexadecimal number to a binary number. This can be done using the base_convert() function.
Parameters
-
data -
Hexadecimal representation of data.
Return Values
Returns the binary representation of the given data or FALSE on failure.
Errors/Exceptions
If the hexadecimal input string is of odd length or invalid hexadecimal string
an E_WARNING level error is thrown.
Changelog
| Version | Description |
|---|---|
| 5.5.1 | A warning is thrown if the input string is invalid hexadecimal string. |
| 5.4.1 | A warning is thrown if the input string is of odd length. In PHP 5.4.0 the string was silently accepted, but the last byte was truncated. |
Examples
Example #1 hex2bin() example
<?php
$hex = hex2bin("6578616d706c65206865782064617461");
var_dump($hex);
?>
The above example will output something similar to:
string(16) "example hex data"
- addcslashes
- addslashes
- bin2hex
- chop
- chr
- chunk_split
- convert_cyr_string
- convert_uudecode
- convert_uuencode
- count_chars
- crc32
- crypt
- echo
- explode
- fprintf
- get_html_translation_table
- hebrev
- hebrevc
- hex2bin
- html_entity_decode
- htmlentities
- htmlspecialchars_decode
- htmlspecialchars
- implode
- join
- lcfirst
- levenshtein
- localeconv
- ltrim
- md5_file
- md5
- metaphone
- money_format
- nl_langinfo
- nl2br
- number_format
- ord
- parse_str
- printf
- quoted_printable_decode
- quoted_printable_encode
- quotemeta
- rtrim
- setlocale
- sha1_file
- sha1
- similar_text
- soundex
- sprintf
- sscanf
- str_getcsv
- str_ireplace
- str_pad
- str_repeat
- str_replace
- str_rot13
- str_shuffle
- str_split
- str_word_count
- strcasecmp
- strchr
- strcmp
- strcoll
- strcspn
- strip_tags
- stripcslashes
- stripos
- stripslashes
- stristr
- strlen
- strnatcasecmp
- strnatcmp
- strncasecmp
- strncmp
- strpbrk
- strpos
- strrchr
- strrev
- strripos
- strrpos
- strspn
- strstr
- strtok
- strtolower
- strtoupper
- strtr
- substr_compare
- substr_count
- substr_replace
- substr
- trim
- ucfirst
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- vfprintf
- vprintf
- vsprintf
- wordwrap
Коментарии
The function hex2bin does not exist in PHP5.
You can use 'pack' instead :
$binary_string = pack("H*" , $hex_string);
The function pack("H*" , $hex_string); will not work as expected if $hex_string contains an odd number of hexadecimal digits.
For example:
<?php echo ord(pack("H*", 'F')); ?>
will return 240 not 15. Use pack("H*", '0F'); instead.
A way to convert hex strings in the form "0x123ABC" to integer is to use the function base_convert("0x123ABC", 16, 10)For those who have php version prior to 5.4, i have a solution to convert hex to binary. It works for me in an encryption and decryption application.
<?php
function hextobin($hexstr)
{
$n = strlen($hexstr);
$sbin="";
$i=0;
while($i<$n)
{
$a =substr($hexstr,$i,2);
$c = pack("H*",$a);
if ($i==0){$sbin=$c;}
else {$sbin.=$c;}
$i+=2;
}
return $sbin;
}
?>
I modified the function by Johnson a bit so it can be used as a drop-in-replacement. You don't need to worry about upgrading php because when it is upgraded, it will use the build in function.
<?php
if ( !function_exists( 'hex2bin' ) ) {
function hex2bin( $str ) {
$sbin = "";
$len = strlen( $str );
for ( $i = 0; $i < $len; $i += 2 ) {
$sbin .= pack( "H*", substr( $str, $i, 2 ) );
}
return $sbin;
}
}
?>
A drop-in hex2bin emulator which behaves just like the the one in v5.5.1.
<?php
if (!function_exists('hex2bin')) {
function hex2bin($data) {
static $old;
if ($old === null) {
$old = version_compare(PHP_VERSION, '5.2', '<');
}
$isobj = false;
if (is_scalar($data) || (($isobj = is_object($data)) && method_exists($data, '__toString'))) {
if ($isobj && $old) {
ob_start();
echo $data;
$data = ob_get_clean();
}
else {
$data = (string) $data;
}
}
else {
trigger_error(__FUNCTION__.'() expects parameter 1 to be string, ' . gettype($data) . ' given', E_USER_WARNING);
return;//null in this case
}
$len = strlen($data);
if ($len % 2) {
trigger_error(__FUNCTION__.'(): Hexadecimal input string must have an even length', E_USER_WARNING);
return false;
}
if (strspn($data, '0123456789abcdefABCDEF') != $len) {
trigger_error(__FUNCTION__.'(): Input string must be hexadecimal string', E_USER_WARNING);
return false;
}
return pack('H*', $data);
}
}
?>
Case of an incomplete hex string following function may help:<?php
function make2validhex($data){
$data = (string) $data;
$len = strlen($data);
if($len % 2) {
return substr($data, 0, $len -1);
}
return $data;
}
?>
test:
<?php
$string="not complete";
echo $string;
echo PHP_EOL;
$hex = bin2hex($string); //"6e6f7420636f6d706c657465"
echo $hex;
echo PHP_EOL;
$deff = substr ($hex, 0, strlen($hex) -1);//"6e6f7420636f6d706c65746"
echo $deff;
echo PHP_EOL;
echo hex2bin(make2validhex($deff)); //"not complet"
echo PHP_EOL;
?>
Ran into an interesting case with hex2bin and php5.5.12 while upgrading from 5.3.3 -> 5.5.12
The previous code had redeclared the hex2bin function with the $binary_string = pack("H*" , $hex_string) trick.
php5.5.12 would have none of that. The solution, albeit a hacky one, was doing a find an replace of hex2bin to 'hex3bin' for the whole site directory.
$test = bin2hex('sample ...');
echo _hex2bin($test);
// another hex2bin replacement
function _hex2bin($result) {
$out = '';
for($c=0;$c<strlen($result);$c+=2) {
$out .= chr(hexdec($result[$c].$result[$c+1]));
} //end for
return (string) $out;
}
replace
function Hex2Bin($data) {
$BinData = "";
for ($i=0;$i<strlen($data);$i+=2)
$BinData .= chr( HexDec( substr($data,$i,2) ) );
return $BinData;
With
function hextobin($hexstr)
{
$n = strlen($hexstr);
$sbin="";
$i=0;
while($i<$n)
{
$a =substr($hexstr,$i,2);
$c = pack("H*",$a);
if ($i==0){$sbin=$c;}
else {$sbin.=$c;}
$i+=2;
}
return $sbin;
If you want to convert hex to GUID format (In my case, it was to convert GUID from MSSQL database) :
<?php
function hex2Guid($hex)
{
$hex = [
substr($hex, 0, 8),
substr($hex, 8, 4),
substr($hex, 12, 4),
substr($hex, 16, 4),
substr($hex, 20),
];
$order[0] = [6, 7, 4, 5, 2, 3, 0, 1];
$order[1] = [2, 3, 0, 1];
$order[2] = [2, 3, 0, 1];
$order[3] = [0, 1, 2, 3];
$order[4] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11];
$result = "";
for($num = 0; $num < count($order); $num++)
{
for($i = 0; $i < count($order[$num]); $i++)
{
$result .= $hex[$num][$order[$num][$i]];
}
if($num != count($order) -1)
{
$result .= "-";
}
}
return strtoupper($result);
}
Example :
echo hex2Guid("64d3938b7008cd4bad5ffe56755d163f");
// return 8B93D364-0870-4BCD-AD5F-FE56755D163F
if you want to convert a hex encoded string to a binary string without any notices/errors regardless of the input, use this function:
<?php
function hex2binary($str)
{
return ctype_xdigit(strlen($str) % 2 ? "" : $str) ? hex2bin($str) : false;
}
hex2binary(""); // false
hex2binary("a"); // false
hex2binary("ab"); // binary-string
?>
if the return type is string, you have your binary-string. otherwise (bool) false.
#error:
hex2bin(): Hexadecimal input string must have an even length
For those who are facing the error above trying to convert hex to bin. you can pad your hex string with initial 0 before hex2bin.
function hexPad(string $hex_string)
{
$st_l = strlen($hex_string);
return str_pad($hex_string, $st_l + ($st_l % 2), '0', STR_PAD_LEFT);
}
hexPad('1bc') -> '01bc';
for usage hex2bin(hexPad('1bc'));