[Console] fix restoring stty mode on CTRL+C

Author: nicolas-grekas

Application.php

@@ -952,6 +952,16 @@ protected function doRunCommand(Command $command, InputInterface $input, OutputI
                 throw new RuntimeException('Unable to subscribe to signal events. Make sure that the `pcntl` extension is installed and that "pcntl_*" functions are not disabled by your php.ini\'s "disable_functions" directive.');
             }
 
+            if (Terminal::hasSttyAvailable()) {
+                $sttyMode = shell_exec('stty -g');
+
+                foreach ([\SIGINT, \SIGTERM] as $signal) {
+                    $this->signalRegistry->register($signal, static function () use ($sttyMode) {
+                        shell_exec('stty '.$sttyMode);
+                    });
+                }
+            }
+
             if ($this->dispatcher) {
                 foreach ($this->signalsToDispatchEvent as $signal) {
                     $event = new ConsoleSignalEvent($command, $input, $output, $signal);

Helper/QuestionHelper.php

@@ -248,6 +248,9 @@ private function autocomplete(OutputInterface $output, Question $question, $inpu
         $numMatches = \count($matches);
 
         $sttyMode = shell_exec('stty -g');
+        $isStdin = 'php://stdin' === (stream_get_meta_data($inputStream)['uri'] ?? null);
+        $r = [$inputStream];
+        $w = [];
 
         // Disable icanon (so we can fread each keypress) and echo (we'll do echoing here instead)
         shell_exec('stty -icanon -echo');
@@ -257,11 +260,15 @@ private function autocomplete(OutputInterface $output, Question $question, $inpu
 
         // Read a keypress
         while (!feof($inputStream)) {
+            while ($isStdin && 0 === @stream_select($r, $w, $w, 0, 100)) {
+                // Give signal handlers a chance to run
+                $r = [$inputStream];
+            }
             $c = fread($inputStream, 1);
 
             // as opposed to fgets(), fread() returns an empty string when the stream content is empty, not false.
             if (false === $c || ('' === $ret && '' === $c && null === $question->getDefault())) {
-                shell_exec(sprintf('stty %s', $sttyMode));
+                shell_exec('stty '.$sttyMode);
                 throw new MissingInputException('Aborted.');
             } elseif ("\177" === $c) { // Backspace Character
                 if (0 === $numMatches && 0 !== $i) {
@@ -366,7 +373,7 @@ function ($match) use ($ret) {
         }
 
         // Reset stty so it behaves normally again
-        shell_exec(sprintf('stty %s', $sttyMode));
+        shell_exec('stty '.$sttyMode);
 
         return $fullChoice;
     }
@@ -427,7 +434,7 @@ private function getHiddenResponse(OutputInterface $output, $inputStream, bool $
         $value = fgets($inputStream, 4096);
 
         if (self::$stty && Terminal::hasSttyAvailable()) {
-            shell_exec(sprintf('stty %s', $sttyMode));
+            shell_exec('stty '.$sttyMode);
         }
 
         if (false === $value) {

Tests/ApplicationTest.php

@@ -38,9 +38,11 @@
 use Symfony\Component\Console\Output\OutputInterface;
 use Symfony\Component\Console\Output\StreamOutput;
 use Symfony\Component\Console\SignalRegistry\SignalRegistry;
+use Symfony\Component\Console\Terminal;
 use Symfony\Component\Console\Tester\ApplicationTester;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\EventDispatcher\EventDispatcher;
+use Symfony\Component\Process\Process;
 
 class ApplicationTest extends TestCase
 {
@@ -1882,6 +1884,39 @@ public function testSignalableCommandInterfaceWithoutSignals()
         $application->add($command);
         $this->assertSame(0, $application->run(new ArrayInput(['signal'])));
     }
+
+    /**
+     * @group tty
+     */
+    public function testSignalableRestoresStty()
+    {
+        if (!Terminal::hasSttyAvailable()) {
+            $this->markTestSkipped('stty not available');
+        }
+
+        if (!SignalRegistry::isSupported()) {
+            $this->markTestSkipped('pcntl signals not available');
+        }
+
+        $previousSttyMode = shell_exec('stty -g');
+
+        $p = new Process(['php', __DIR__.'/Fixtures/application_signalable.php']);
+        $p->setTty(true);
+        $p->start();
+
+        for ($i = 0; $i < 10 && shell_exec('stty -g') === $previousSttyMode; ++$i) {
+            usleep(100000);
+        }
+
+        $this->assertNotSame($previousSttyMode, shell_exec('stty -g'));
+        $p->signal(\SIGINT);
+        $p->wait();
+
+        $sttyMode = shell_exec('stty -g');
+        shell_exec('stty '.$previousSttyMode);
+
+        $this->assertSame($previousSttyMode, $sttyMode);
+    }
 }
 
 class CustomApplication extends Application

Tests/Fixtures/application_signalable.php

@@ -0,0 +1,36 @@
+<?php
+
+use Symfony\Component\Console\Application;
+use Symfony\Component\Console\Command\SignalableCommandInterface;
+use Symfony\Component\Console\Helper\QuestionHelper;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Question\ChoiceQuestion;
+use Symfony\Component\Console\SingleCommandApplication;
+
+$vendor = __DIR__;
+while (!file_exists($vendor.'/vendor')) {
+    $vendor = \dirname($vendor);
+}
+require $vendor.'/vendor/autoload.php';
+
+(new class() extends SingleCommandApplication implements SignalableCommandInterface {
+    public function getSubscribedSignals(): array
+    {
+        return [SIGINT];
+    }
+
+    public function handleSignal(int $signal): void
+    {
+        exit;
+    }
+})
+    ->setCode(function(InputInterface $input, OutputInterface $output) {
+        $this->getHelper('question')
+             ->ask($input, $output, new ChoiceQuestion('😊', ['y']));
+
+        return 0;
+    })
+    ->run()
+
+;