Question

While looking over some code, I found a function that seems to do exactly what bin2hex does. I tested on large sets of randomly generated input and they were identical. What I would like to know is if anyone can see any difference between them. Or maybe someone can give me some information about the implementation of bin2hex.

Here is the function I was telling you about:

function strToHex($str){
    $result='';
    $map = array(
        '0' => '00',
        '1' => '01',
        '2' => '02',
        '3' => '03',
        '4' => '04',
        '5' => '05',
        '6' => '06',
        '7' => '07',
        '8' => '08',
        '9' => '09',
        'a' => '0a',
        'b' => '0b',
        'c' => '0c',
        'd' => '0d',
        'e' => '0e',
        'f' => '0f'
    );

    for ($i=0; $i < strlen($str); $i++){
        $tmp = dechex(ord($str[$i]));
        if(isset( $map[$tmp]))
            $tmp = $map[$tmp];
        $result .= $tmp;
    }

    return $result;
}

Thank you,
Alin

Answer 1

I do not know the implementation details in PHP, but you can take a look of this javascript function (from the php.js) it is the equivalent to PHP bin2hex but written in JS.

function bin2hex (s) {
// http://kevin.vanzonneveld.net
// +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
// +   bugfixed by: Onno Marsman
// +   bugfixed by: Linuxworld
// *     example 1: bin2hex('Kev');
// *     returns 1: '4b6576'
// *     example 2: bin2hex(String.fromCharCode(0x00));
// *     returns 2: '00'
var i, f = 0,
    a = [];

s += '';
f = s.length;

for (i = 0; i < f; i++) {
    a[i] = s.charCodeAt(i).toString(16).replace(/^([\da-f])$/, "0$1");
}

return a.join('');

}

You can see the original code here

HTH!