Is there a native PHP function for converting a string to its HEX representation that can be then eval()'d as a string, such as:
"ABC" => "\x41\x42\x43"
I know it can be done in several steps, I'm just wondering if I'm unnecessarily complicating something that could be done with a single, native function?
There is no native function, but you can use hex2bin to eval PHP code which is in hex, e.g.
eval(hex2bin("6563686f20706928293b")); # Output: 3.14159265359
eval(hex2bin(bin2hex("echo pi();"))); # Behind the scenes.
Or you can call the function which name is in hex string:
$ echo '<?$_=hex2bin(7069);die($_());' | php # 7069 = pi
3.14159265359
var_export() but exporting the values as hex only!There is no built in PHP function to achieve the same results, but with some PHP-Fu you can do it in one line:
$str = 'ABC';
$str = '\x'.implode('\x', str_split(bin2hex($str), 2));
echo $str; // \x41\x42\x43
There is also a piece of code in the PHP docs which gives exactly the same results:
$str = 'ABC';
$field=bin2hex($str);
$field=chunk_split($field,2,"\\x");
$field= "\\x" . substr($field,0,-2);
echo $field; // \x41\x42\x43
$n = 1234;
echo printf("%x", $n); //should return the hexadecimal format of the number
Why don't you try something like this?
function strtohex($string) {
if (!empty($string)) {
$output = null;
$count = strlen($string, "UTF-8");
for ($i = 0; $i < $count; $i++) {
$output .= dechex(ord($string[$i]));
}
return $output;
}
}
For one-liners, the only alternative I can think about is the bin2hex() function, which is native in PHP and it offers the same.
$string[$i] will only return one byte. To retrieve one character from a UTF-8 string, you need to use mb_substr().
bin2hex(), then you'd have to add the\xto each character manually:'\x' . implode( '\x', array_map( 'bin2hex', str_split( 'ABC'))));eval()'dif it is astring?"\x41\x42\x43"is valid PHP, and could be eval'd.