<?php
session_name("a3e0f0ee-9f5a-4be2-88cb-3b7ceb626d00");
session_start();
function get(string $id, string $name): ?string {
$file = __DIR__ . "/../_runners/$id/results/" . $name;
if (!is_file($file))
return null;
return file_get_contents($file);
}
function csrf_token(): string {
return $_SESSION["csrf-token"] = base64_encode(random_bytes(30));
}
function getid(): string {
return str_pad(bin2hex(random_bytes(16)), 32, "0", STR_PAD_LEFT);
}
function delTree($dir) {
foreach (scandir($dir) as $ent) {
if ($ent === "." || $ent === "..")
continue;
$path = $dir . DIRECTORY_SEPARATOR . $ent;
if (is_dir($path))
delTree($path);
else
unlink($path);
}
return rmdir($dir);
}
function file_cachebuster(string $filename): string {
return htmlentities(urlencode(md5(
strval(filemtime($filename)) .
strval(filesize($filename))
)));
}
$defaultCode = <<<java
public class Program {
public static void main(String[] args) {
// Your code here
System.out.println("Hello, world!");
}
}
java;
const CODE_MAXLENGTH = 16383;
$code = null;
if (!empty($_GET["c"])) {
$compressedCode = @base64_decode($_GET["c"], true);
if ($compressedCode !== false) {
$uncompressedCode = @gzinflate($compressedCode, CODE_MAXLENGTH);
if ($compressedCode !== false) {
$code = &$uncompressedCode;
}
}
}
$result = null;
if (isset($_POST["code"]) && strlen($_POST["code"]) <= CODE_MAXLENGTH) {
header("Content-Type: application/json");
$code = $_POST["code"];
$csrf = $_POST["csrf"] ?? null;
if ($csrf === null || $csrf !== $_SESSION["csrf-token"]) {
echo json_encode([
"ok" => false,
"message" => "CSRF token mismatch",
"csrf" => csrf_token(),
]);
exit;
}
if (($_POST["permalink"] ?? "") === "1") {
echo json_encode([
"ok" => true,
"data" => base64_encode(gzdeflate($code, 9, ZLIB_ENCODING_RAW)),
]);
exit;
}
$id = getid();
$runnerDir = __DIR__ . "/../_runners/$id";
$srcDir = $runnerDir . "/src";
mkdir($srcDir, recursive: true);
file_put_contents($srcDir . "/Program.java", $code);
$isInDocker = getenv("IS_IN_DOCKER") === "1";
if ($isInDocker)
file_put_contents("php://stderr", "[debug] In Docker\n");
chdir(__DIR__ . "/..");
$stderrFile = sys_get_temp_dir() . "/tmp{$id}.2";
exec(
($isInDocker ? "su-exec root " : "") .
"./compile-and-run.sh '$id' Program 2>'$stderrFile'", $resultStr, $code);
$resultStr = implode("\n", $resultStr);
if (is_file($stderrFile)) {
$stderrContents = file_get_contents($stderrFile);
unlink($stderrFile);
if (!empty($stderrContents)) {
file_put_contents("php://stderr", "compile-and-run.sh failed: $stderrContents\n");
if ($code != 0) {
echo json_encode([
"ok" => false,
"message" => "Execution failed:\n$stderrContents",
"csrf" => csrf_token(),
]);
delTree($runnerDir);
exit;
}
}
}
chdir(__DIR__);
file_put_contents("php://stderr", "result: $result\n");
$csrf = csrf_token();
$result = [
"compile" => [
"status" => get($id, "c.s"),
"stdout" => get($id, "c.0"),
"stderr" => get($id, "c.1"),
],
"run" => [
"status" => get($id, "r.s"),
"stdout" => get($id, "r.0"),
"stderr" => get($id, "r.1"),
],
"runner" => $id,
"ok" => true,
"csrf" => $csrf,
];
if ($isInDocker)
exec("su-exec root rm -rf '$runnerDir'");
else
delTree($runnerDir);
echo json_encode($result);
exit;
}
$csrf = csrf_token();
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Java</title>
<link rel="stylesheet" href="dist/codemirror.css">
<link rel="stylesheet" href="dist/eclipse.css">
<link rel="stylesheet" href="site.css?_=<?= file_cachebuster(__DIR__ . "/site.css") ?>">
<script src="dist/jquery-1.12.4.min.js"></script>
<script src="dist/codemirror.js"></script>
<script src="dist/clike.js"></script>
<script src="site.js?_=<?= file_cachebuster(__DIR__ . "/site.js") ?>"></script>
</head>
<body>
<div id="loader" style="display: none;">
<div id="spinner"></div>
</div>
<h1>☕️ Java Compiler</h1>
<p>Powered by Eclipse Temurin</p>
<form method="POST">
<input name="csrf" id="csrf-token" type="hidden" value="<?= htmlentities($csrf) ?>">
<textarea maxlength="<?= CODE_MAXLENGTH ?>" id="editor" name="code" rows="20"><?= htmlentities($code ?? $defaultCode) ?></textarea>
<div id="toolbar">
<button type="submit">▶️ Compile & run</button>
<button type="button" id="dlCodeButton">💾️ Download code as file</button>
<button type="button" id="permalink">🔗️ Permalink</button>
</div>
</form>
<div id="output" style="display: none;"></div>
<div id="footer">
© <?= date("Y") ?> <a href="https://jkohl.link/" target="_blank">Jonas Kohl</a>.
<a href="https://git.jkohl.link/online-java-compiler.git" target="_blank">Source code</a>.
<a href="javascript:;" id="toggleFullWidth">Toggle full width</a>
</div>
</body>
</html>