leftypol/inc/error.php

<?php

function error_handler($errno, $errstr, $errfile, $errline) {
	if (error_reporting() & $errno) {
		$config['debug'] = true;
		error("$errstr in $errfile at line $errline");
	}
	return false;
}

function exception_handler($e) {
	error_log($e);
	error($e->getMessage());
}

set_exception_handler('exception_handler');

function fatal_error_handler() {
	if (($error = error_get_last()) && $error['type'] == E_ERROR) {
		error("Caught fatal error: {$error['message']} in {$error['file']} at line {$error['line']}");
	}
}

register_shutdown_function('fatal_error_handler');

// Due to composer autoload, this isn't implicitly global anymore
global $error_recursion;
$error_recursion = false;

function error($message, $priority = true, $debug_stuff = false) {
	global $board, $mod, $config, $db_error, $error_recursion;

	if($error_recursion !== false) {
		die("Error recursion detected with $message<br>Original error: $error_recursion");
	}

	$error_recursion = $message;

	if (defined('STDIN')) {
		// Running from CLI
		echo("Error: $message\n");
		debug_print_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
		die();
	}

	if (!empty($config)) {
		if ($config['syslog'] && $priority !== false) {
			// Use LOG_NOTICE instead of LOG_ERR or LOG_WARNING because most error message are not significant.
			_syslog($priority !== true ? $priority : LOG_NOTICE, $message);
		}

		if ($config['debug']) {
			$debug_stuff = [];
			if (isset($db_error)) {
				$debug_stuff = array_combine([ 'SQLSTATE', 'Error code', 'Error message' ], $db_error);
			}
			$debug_stuff['backtrace'] = debug_backtrace();
			$pw = $config['db']['password'];
			$debug_callback = function($item) use (&$debug_callback, $pw) {
				if (is_array($item)) {
					$item = array_filter($item, $debug_callback);
				}
				return $item !== $pw || !$pw;
			};
			$debug_stuff = array_map($debug_callback, $debug_stuff);
		}
	}

	if (isset($_POST['json_response'])) {
		header('Content-Type: text/json; charset=utf-8');
		$data = [ 'error' => $message ];
		if (!empty($config) && $config['debug']) {
			$data['debug'] = $debug_stuff;
		}
		print json_encode($data);
		exit();
	}

	header("{$_SERVER['SERVER_PROTOCOL']} 500 Internal Server Error");

	die(Element('page.html', [
		'config' => $config,
		'title' => _('Error'),
		'subtitle' => _('An error has occured.'),
		'body' => Element('error.html', array(
			'config' => $config,
			'message' => $message,
			'mod' => $mod,
			'board' => isset($board) ? $board : false,
			'debug' => str_replace("\n", '&#10;', utf8tohtml(print_r($debug_stuff, true)))
		))
	]));
}