debug()

debug.php

<?php
/**
 * @link https://gist.github.com/lav45/31f9744049c5bca13a46
 * @author Alexey Loban <lav451@gmail.com>
 *
 * Example:
 *    debug();
 *    debug($_POST);
 *    debug($_GET, $_POST, ...);
 *
 * Nginx:
 *      fastcgi_param PHP_VALUE "auto_prepend_file=/path_to/debug.php";
 *
 * Apache:
 *      php_value auto_prepend_file "/path_to/debug.php"
 *
 * Php CLI:
 *      mkdir -p ~/.php.d
 *      echo 'auto_prepend_file=/path_to/debug.php' >> ~/.php.d/php.ini
 *      echo 'export PHP_INI_SCAN_DIR=:~/.php.d' >> ~/.bashrc
 */

function debug()
{
    // Install: https://chrome.google.com/webstore/detail/xdebug-helper/eadndfjplgieldjbigjakmdgkmoaaaoc
    // if (empty($_COOKIE['XDEBUG_SESSION'])) return;
    
    ob_get_level() && ob_clean();
    $wrap = true;
    switch (func_num_args()) {
        case 0:
            $res = (new \Exception())->getTraceAsString();
            $wrap = false;
            break;
        case 1:
            $res = func_get_arg(0);
            break;
        default:
            $res = func_get_args();
            break;
    }
    if ($wrap && !is_string($data)) {
        $func = is_scalar($data) || null === $data ? 'var_export' : 'print_r';
        $data = $func($data, true);
    }

    $isAjax = isset($_SERVER['HTTP_X_REQUESTED_WITH']) &&
        $_SERVER['HTTP_X_REQUESTED_WITH'] === 'XMLHttpRequest' &&
        $_SERVER['HTTP_CONTENT_TYPE'] === 'application/json';

    $isHtml = isset($_SERVER['HTTP_ACCEPT']) && strpos($_SERVER['HTTP_ACCEPT'], 'text/html') !== false;

    if ($isHtml && !$isAjax) {
        $res = '<pre>' . htmlspecialchars($res, ENT_IGNORE) . '</pre>';    
    }
    exit($res);
}