<?php

/**
 * Print binary data as hex string
 * @param string $data
 * @param string $newline
 * @param int    $width
 */
function hexdump($data, $newline = "\n", $width = 16) {
    static $from = '';
    static $to = '';

    static $pad = '.'; # padding for non-visible characters

    if ($from === '') {
        for ($i = 0; $i <= 0xFF; $i++) {
            $from .= chr($i);
            $to .= ($i >= 0x20 && $i <= 0x7E) ? chr($i) : $pad;
        }
    }

    $hex = str_split(bin2hex($data), $width * 2);
    $chars = str_split(strtr($data, $from, $to), $width);

    $offset = 0;
    foreach ($hex as $i => $line) {
        echo sprintf('%06X', $offset) . ' : ' . str_pad(implode(' ', str_split($line, 2)), $width * 3) . '  ' . $chars[$i] . $newline;
        $offset += $width;
    }
}