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<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Process;

use
Symfony\Component\Process\Exception\InvalidArgumentException;
use
Symfony\Component\Process\Exception\LogicException;
use
Symfony\Component\Process\Exception\ProcessFailedException;
use
Symfony\Component\Process\Exception\ProcessTimedOutException;
use
Symfony\Component\Process\Exception\RuntimeException;
use
Symfony\Component\Process\Pipes\PipesInterface;
use
Symfony\Component\Process\Pipes\UnixPipes;
use
Symfony\Component\Process\Pipes\WindowsPipes;

/**
 * Process is a thin wrapper around proc_* functions to easily
 * start independent PHP processes.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 * @author Romain Neutron <imprec@gmail.com>
 */
class Process implements \IteratorAggregate
{
    const
ERR = 'err';
    const
OUT = 'out';

    const
STATUS_READY = 'ready';
    const
STATUS_STARTED = 'started';
    const
STATUS_TERMINATED = 'terminated';

    const
STDIN = 0;
    const
STDOUT = 1;
    const
STDERR = 2;

   
// Timeout Precision in seconds.
   
const TIMEOUT_PRECISION = 0.2;

    const
ITER_NON_BLOCKING = 1; // By default, iterating over outputs is a blocking call, use this flag to make it non-blocking
   
const ITER_KEEP_OUTPUT = 2;  // By default, outputs are cleared while iterating, use this flag to keep them in memory
   
const ITER_SKIP_OUT = 4;     // Use this flag to skip STDOUT while iterating
   
const ITER_SKIP_ERR = 8;     // Use this flag to skip STDERR while iterating

   
private $callback;
    private
$hasCallback = false;
    private
$commandline;
    private
$cwd;
    private
$env;
    private
$input;
    private
$starttime;
    private
$lastOutputTime;
    private
$timeout;
    private
$idleTimeout;
    private
$options = ['suppress_errors' => true];
    private
$exitcode;
    private
$fallbackStatus = [];
    private
$processInformation;
    private
$outputDisabled = false;
    private
$stdout;
    private
$stderr;
    private
$enhanceWindowsCompatibility = true;
    private
$enhanceSigchildCompatibility;
    private
$process;
    private
$status = self::STATUS_READY;
    private
$incrementalOutputOffset = 0;
    private
$incrementalErrorOutputOffset = 0;
    private
$tty = false;
    private
$pty;
    private
$inheritEnv = false;

    private
$useFileHandles = false;
   
/** @var PipesInterface */
   
private $processPipes;

    private
$latestSignal;

    private static
$sigchild;

   
/**
     * Exit codes translation table.
     *
     * User-defined errors must use exit codes in the 64-113 range.
     */
   
public static $exitCodes = [
       
0 => 'OK',
       
1 => 'General error',
       
2 => 'Misuse of shell builtins',

       
126 => 'Invoked command cannot execute',
       
127 => 'Command not found',
       
128 => 'Invalid exit argument',

       
// signals
       
129 => 'Hangup',
       
130 => 'Interrupt',
       
131 => 'Quit and dump core',
       
132 => 'Illegal instruction',
       
133 => 'Trace/breakpoint trap',
       
134 => 'Process aborted',
       
135 => 'Bus error: "access to undefined portion of memory object"',
       
136 => 'Floating point exception: "erroneous arithmetic operation"',
       
137 => 'Kill (terminate immediately)',
       
138 => 'User-defined 1',
       
139 => 'Segmentation violation',
       
140 => 'User-defined 2',
       
141 => 'Write to pipe with no one reading',
       
142 => 'Signal raised by alarm',
       
143 => 'Termination (request to terminate)',
       
// 144 - not defined
       
145 => 'Child process terminated, stopped (or continued*)',
       
146 => 'Continue if stopped',
       
147 => 'Stop executing temporarily',
       
148 => 'Terminal stop signal',
       
149 => 'Background process attempting to read from tty ("in")',
       
150 => 'Background process attempting to write to tty ("out")',
       
151 => 'Urgent data available on socket',
       
152 => 'CPU time limit exceeded',
       
153 => 'File size limit exceeded',
       
154 => 'Signal raised by timer counting virtual time: "virtual timer expired"',
       
155 => 'Profiling timer expired',
       
// 156 - not defined
       
157 => 'Pollable event',
       
// 158 - not defined
       
159 => 'Bad syscall',
    ];

   
/**
     * @param string|array   $commandline The command line to run
     * @param string|null    $cwd         The working directory or null to use the working dir of the current PHP process
     * @param array|null     $env         The environment variables or null to use the same environment as the current PHP process
     * @param mixed|null     $input       The input as stream resource, scalar or \Traversable, or null for no input
     * @param int|float|null $timeout     The timeout in seconds or null to disable
     * @param array          $options     An array of options for proc_open
     *
     * @throws RuntimeException When proc_open is not installed
     */
   
public function __construct($commandline, $cwd = null, array $env = null, $input = null, $timeout = 60, array $options = null)
    {
        if (!\
function_exists('proc_open')) {
            throw new
RuntimeException('The Process class relies on proc_open, which is not available on your PHP installation.');
        }

       
$this->commandline = $commandline;
       
$this->cwd = $cwd;

       
// on Windows, if the cwd changed via chdir(), proc_open defaults to the dir where PHP was started
        // on Gnu/Linux, PHP builds with --enable-maintainer-zts are also affected
        // @see : https://bugs.php.net/51800
        // @see : https://bugs.php.net/50524
       
if (null === $this->cwd && (\defined('ZEND_THREAD_SAFE') || '\\' === \DIRECTORY_SEPARATOR)) {
           
$this->cwd = getcwd();
        }
        if (
null !== $env) {
           
$this->setEnv($env);
        }

       
$this->setInput($input);
       
$this->setTimeout($timeout);
       
$this->useFileHandles = '\\' === \DIRECTORY_SEPARATOR;
       
$this->pty = false;
       
$this->enhanceSigchildCompatibility = '\\' !== \DIRECTORY_SEPARATOR && $this->isSigchildEnabled();
        if (
null !== $options) {
            @
trigger_error(sprintf('The $options parameter of the %s constructor is deprecated since Symfony 3.3 and will be removed in 4.0.', __CLASS__), \E_USER_DEPRECATED);
           
$this->options = array_replace($this->options, $options);
        }
    }

    public function
__destruct()
    {
       
$this->stop(0);
    }

    public function
__clone()
    {
       
$this->resetProcessData();
    }

   
/**
     * Runs the process.
     *
     * The callback receives the type of output (out or err) and
     * some bytes from the output in real-time. It allows to have feedback
     * from the independent process during execution.
     *
     * The STDOUT and STDERR are also available after the process is finished
     * via the getOutput() and getErrorOutput() methods.
     *
     * @param callable|null $callback A PHP callback to run whenever there is some
     *                                output available on STDOUT or STDERR
     *
     * @return int The exit status code
     *
     * @throws RuntimeException When process can't be launched
     * @throws RuntimeException When process stopped after receiving signal
     * @throws LogicException   In case a callback is provided and output has been disabled
     *
     * @final since version 3.3
     */
   
public function run($callback = null/*, array $env = []*/)
    {
       
$env = 1 < \func_num_args() ? func_get_arg(1) : null;
       
$this->start($callback, $env);

        return
$this->wait();
    }

   
/**
     * Runs the process.
     *
     * This is identical to run() except that an exception is thrown if the process
     * exits with a non-zero exit code.
     *
     * @return $this
     *
     * @throws RuntimeException       if PHP was compiled with --enable-sigchild and the enhanced sigchild compatibility mode is not enabled
     * @throws ProcessFailedException if the process didn't terminate successfully
     *
     * @final since version 3.3
     */
   
public function mustRun(callable $callback = null/*, array $env = []*/)
    {
        if (!
$this->enhanceSigchildCompatibility && $this->isSigchildEnabled()) {
            throw new
RuntimeException('This PHP has been compiled with --enable-sigchild. You must use setEnhanceSigchildCompatibility() to use this method.');
        }
       
$env = 1 < \func_num_args() ? func_get_arg(1) : null;

        if (
0 !== $this->run($callback, $env)) {
            throw new
ProcessFailedException($this);
        }

        return
$this;
    }

   
/**
     * Starts the process and returns after writing the input to STDIN.
     *
     * This method blocks until all STDIN data is sent to the process then it
     * returns while the process runs in the background.
     *
     * The termination of the process can be awaited with wait().
     *
     * The callback receives the type of output (out or err) and some bytes from
     * the output in real-time while writing the standard input to the process.
     * It allows to have feedback from the independent process during execution.
     *
     * @param callable|null $callback A PHP callback to run whenever there is some
     *                                output available on STDOUT or STDERR
     *
     * @throws RuntimeException When process can't be launched
     * @throws RuntimeException When process is already running
     * @throws LogicException   In case a callback is provided and output has been disabled
     */
   
public function start(callable $callback = null/*, array $env = [*/)
    {
        if (
$this->isRunning()) {
            throw new
RuntimeException('Process is already running.');
        }
        if (
2 <= \func_num_args()) {
           
$env = func_get_arg(1);
        } else {
            if (
__CLASS__ !== static::class) {
               
$r = new \ReflectionMethod($this, __FUNCTION__);
                if (
__CLASS__ !== $r->getDeclaringClass()->getName() && (2 > $r->getNumberOfParameters() || 'env' !== $r->getParameters()[1]->name)) {
                    @
trigger_error(sprintf('The %s::start() method expects a second "$env" argument since Symfony 3.3. It will be made mandatory in 4.0.', static::class), \E_USER_DEPRECATED);
                }
            }
           
$env = null;
        }

       
$this->resetProcessData();
       
$this->starttime = $this->lastOutputTime = microtime(true);
       
$this->callback = $this->buildCallback($callback);
       
$this->hasCallback = null !== $callback;
       
$descriptors = $this->getDescriptors();
       
$inheritEnv = $this->inheritEnv;

        if (\
is_array($commandline = $this->commandline)) {
           
$commandline = implode(' ', array_map([$this, 'escapeArgument'], $commandline));

            if (
'\\' !== \DIRECTORY_SEPARATOR) {
               
// exec is mandatory to deal with sending a signal to the process
               
$commandline = 'exec '.$commandline;
            }
        }

        if (
null === $env) {
           
$env = $this->env;
        } else {
            if (
$this->env) {
               
$env += $this->env;
            }
           
$inheritEnv = true;
        }

        if (
null !== $env && $inheritEnv) {
           
$env += $this->getDefaultEnv();
        } elseif (
null !== $env) {
            @
trigger_error('Not inheriting environment variables is deprecated since Symfony 3.3 and will always happen in 4.0. Set "Process::inheritEnvironmentVariables()" to true instead.', \E_USER_DEPRECATED);
        } else {
           
$env = $this->getDefaultEnv();
        }
        if (
'\\' === \DIRECTORY_SEPARATOR && $this->enhanceWindowsCompatibility) {
           
$this->options['bypass_shell'] = true;
           
$commandline = $this->prepareWindowsCommandLine($commandline, $env);
        } elseif (!
$this->useFileHandles && $this->enhanceSigchildCompatibility && $this->isSigchildEnabled()) {
           
// last exit code is output on the fourth pipe and caught to work around --enable-sigchild
           
$descriptors[3] = ['pipe', 'w'];

           
// See https://unix.stackexchange.com/questions/71205/background-process-pipe-input
           
$commandline = '{ ('.$commandline.') <&3 3<&- 3>/dev/null & } 3<&0;';
           
$commandline .= 'pid=$!; echo $pid >&3; wait $pid; code=$?; echo $code >&3; exit $code';

           
// Workaround for the bug, when PTS functionality is enabled.
            // @see : https://bugs.php.net/69442
           
$ptsWorkaround = fopen(__FILE__, 'r');
        }
        if (\
defined('HHVM_VERSION')) {
           
$envPairs = $env;
        } else {
           
$envPairs = [];
            foreach (
$env as $k => $v) {
                if (
false !== $v) {
                   
$envPairs[] = $k.'='.$v;
                }
            }
        }

        if (!
is_dir($this->cwd)) {
            @
trigger_error('The provided cwd does not exist. Command is currently ran against getcwd(). This behavior is deprecated since Symfony 3.4 and will be removed in 4.0.', \E_USER_DEPRECATED);
        }

       
$this->process = @proc_open($commandline, $descriptors, $this->processPipes->pipes, $this->cwd, $envPairs, $this->options);

        if (!\
is_resource($this->process)) {
            throw new
RuntimeException('Unable to launch a new process.');
        }
       
$this->status = self::STATUS_STARTED;

        if (isset(
$descriptors[3])) {
           
$this->fallbackStatus['pid'] = (int) fgets($this->processPipes->pipes[3]);
        }

        if (
$this->tty) {
            return;
        }

       
$this->updateStatus(false);
       
$this->checkTimeout();
    }

   
/**
     * Restarts the process.
     *
     * Be warned that the process is cloned before being started.
     *
     * @param callable|null $callback A PHP callback to run whenever there is some
     *                                output available on STDOUT or STDERR
     *
     * @return static
     *
     * @throws RuntimeException When process can't be launched
     * @throws RuntimeException When process is already running
     *
     * @see start()
     *
     * @final since version 3.3
     */
   
public function restart(callable $callback = null/*, array $env = []*/)
    {
        if (
$this->isRunning()) {
            throw new
RuntimeException('Process is already running.');
        }
       
$env = 1 < \func_num_args() ? func_get_arg(1) : null;

       
$process = clone $this;
       
$process->start($callback, $env);

        return
$process;
    }

   
/**
     * Waits for the process to terminate.
     *
     * The callback receives the type of output (out or err) and some bytes
     * from the output in real-time while writing the standard input to the process.
     * It allows to have feedback from the independent process during execution.
     *
     * @param callable|null $callback A valid PHP callback
     *
     * @return int The exitcode of the process
     *
     * @throws RuntimeException When process timed out
     * @throws RuntimeException When process stopped after receiving signal
     * @throws LogicException   When process is not yet started
     */
   
public function wait(callable $callback = null)
    {
       
$this->requireProcessIsStarted(__FUNCTION__);

       
$this->updateStatus(false);

        if (
null !== $callback) {
            if (!
$this->processPipes->haveReadSupport()) {
               
$this->stop(0);
                throw new \
LogicException('Pass the callback to the Process::start method or enableOutput to use a callback with Process::wait.');
            }
           
$this->callback = $this->buildCallback($callback);
        }

        do {
           
$this->checkTimeout();
           
$running = '\\' === \DIRECTORY_SEPARATOR ? $this->isRunning() : $this->processPipes->areOpen();
           
$this->readPipes($running, '\\' !== \DIRECTORY_SEPARATOR || !$running);
        } while (
$running);

        while (
$this->isRunning()) {
           
$this->checkTimeout();
           
usleep(1000);
        }

        if (
$this->processInformation['signaled'] && $this->processInformation['termsig'] !== $this->latestSignal) {
            throw new
RuntimeException(sprintf('The process has been signaled with signal "%s".', $this->processInformation['termsig']));
        }

        return
$this->exitcode;
    }

   
/**
     * Returns the Pid (process identifier), if applicable.
     *
     * @return int|null The process id if running, null otherwise
     */
   
public function getPid()
    {
        return
$this->isRunning() ? $this->processInformation['pid'] : null;
    }

   
/**
     * Sends a POSIX signal to the process.
     *
     * @param int $signal A valid POSIX signal (see https://php.net/pcntl.constants)
     *
     * @return $this
     *
     * @throws LogicException   In case the process is not running
     * @throws RuntimeException In case --enable-sigchild is activated and the process can't be killed
     * @throws RuntimeException In case of failure
     */
   
public function signal($signal)
    {
       
$this->doSignal($signal, true);

        return
$this;
    }

   
/**
     * Disables fetching output and error output from the underlying process.
     *
     * @return $this
     *
     * @throws RuntimeException In case the process is already running
     * @throws LogicException   if an idle timeout is set
     */
   
public function disableOutput()
    {
        if (
$this->isRunning()) {
            throw new
RuntimeException('Disabling output while the process is running is not possible.');
        }
        if (
null !== $this->idleTimeout) {
            throw new
LogicException('Output can not be disabled while an idle timeout is set.');
        }

       
$this->outputDisabled = true;

        return
$this;
    }

   
/**
     * Enables fetching output and error output from the underlying process.
     *
     * @return $this
     *
     * @throws RuntimeException In case the process is already running
     */
   
public function enableOutput()
    {
        if (
$this->isRunning()) {
            throw new
RuntimeException('Enabling output while the process is running is not possible.');
        }

       
$this->outputDisabled = false;

        return
$this;
    }

   
/**
     * Returns true in case the output is disabled, false otherwise.
     *
     * @return bool
     */
   
public function isOutputDisabled()
    {
        return
$this->outputDisabled;
    }

   
/**
     * Returns the current output of the process (STDOUT).
     *
     * @return string The process output
     *
     * @throws LogicException in case the output has been disabled
     * @throws LogicException In case the process is not started
     */
   
public function getOutput()
    {
       
$this->readPipesForOutput(__FUNCTION__);

        if (
false === $ret = stream_get_contents($this->stdout, -1, 0)) {
            return
'';
        }

        return
$ret;
    }

   
/**
     * Returns the output incrementally.
     *
     * In comparison with the getOutput method which always return the whole
     * output, this one returns the new output since the last call.
     *
     * @return string The process output since the last call
     *
     * @throws LogicException in case the output has been disabled
     * @throws LogicException In case the process is not started
     */
   
public function getIncrementalOutput()
    {
       
$this->readPipesForOutput(__FUNCTION__);

       
$latest = stream_get_contents($this->stdout, -1, $this->incrementalOutputOffset);
       
$this->incrementalOutputOffset = ftell($this->stdout);

        if (
false === $latest) {
            return
'';
        }

        return
$latest;
    }

   
/**
     * Returns an iterator to the output of the process, with the output type as keys (Process::OUT/ERR).
     *
     * @param int $flags A bit field of Process::ITER_* flags
     *
     * @throws LogicException in case the output has been disabled
     * @throws LogicException In case the process is not started
     *
     * @return \Generator
     */
   
public function getIterator($flags = 0)
    {
       
$this->readPipesForOutput(__FUNCTION__, false);

       
$clearOutput = !(self::ITER_KEEP_OUTPUT & $flags);
       
$blocking = !(self::ITER_NON_BLOCKING & $flags);
       
$yieldOut = !(self::ITER_SKIP_OUT & $flags);
       
$yieldErr = !(self::ITER_SKIP_ERR & $flags);

        while (
null !== $this->callback || ($yieldOut && !feof($this->stdout)) || ($yieldErr && !feof($this->stderr))) {
            if (
$yieldOut) {
               
$out = stream_get_contents($this->stdout, -1, $this->incrementalOutputOffset);

                if (isset(
$out[0])) {
                    if (
$clearOutput) {
                       
$this->clearOutput();
                    } else {
                       
$this->incrementalOutputOffset = ftell($this->stdout);
                    }

                    yield
self::OUT => $out;
                }
            }

            if (
$yieldErr) {
               
$err = stream_get_contents($this->stderr, -1, $this->incrementalErrorOutputOffset);

                if (isset(
$err[0])) {
                    if (
$clearOutput) {
                       
$this->clearErrorOutput();
                    } else {
                       
$this->incrementalErrorOutputOffset = ftell($this->stderr);
                    }

                    yield
self::ERR => $err;
                }
            }

            if (!
$blocking && !isset($out[0]) && !isset($err[0])) {
                yield
self::OUT => '';
            }

           
$this->checkTimeout();
           
$this->readPipesForOutput(__FUNCTION__, $blocking);
        }
    }

   
/**
     * Clears the process output.
     *
     * @return $this
     */
   
public function clearOutput()
    {
       
ftruncate($this->stdout, 0);
       
fseek($this->stdout, 0);
       
$this->incrementalOutputOffset = 0;

        return
$this;
    }

   
/**
     * Returns the current error output of the process (STDERR).
     *
     * @return string The process error output
     *
     * @throws LogicException in case the output has been disabled
     * @throws LogicException In case the process is not started
     */
   
public function getErrorOutput()
    {
       
$this->readPipesForOutput(__FUNCTION__);

        if (
false === $ret = stream_get_contents($this->stderr, -1, 0)) {
            return
'';
        }

        return
$ret;
    }

   
/**
     * Returns the errorOutput incrementally.
     *
     * In comparison with the getErrorOutput method which always return the
     * whole error output, this one returns the new error output since the last
     * call.
     *
     * @return string The process error output since the last call
     *
     * @throws LogicException in case the output has been disabled
     * @throws LogicException In case the process is not started
     */
   
public function getIncrementalErrorOutput()
    {
       
$this->readPipesForOutput(__FUNCTION__);

       
$latest = stream_get_contents($this->stderr, -1, $this->incrementalErrorOutputOffset);
       
$this->incrementalErrorOutputOffset = ftell($this->stderr);

        if (
false === $latest) {
            return
'';
        }

        return
$latest;
    }

   
/**
     * Clears the process output.
     *
     * @return $this
     */
   
public function clearErrorOutput()
    {
       
ftruncate($this->stderr, 0);
       
fseek($this->stderr, 0);
       
$this->incrementalErrorOutputOffset = 0;

        return
$this;
    }

   
/**
     * Returns the exit code returned by the process.
     *
     * @return int|null The exit status code, null if the Process is not terminated
     *
     * @throws RuntimeException In case --enable-sigchild is activated and the sigchild compatibility mode is disabled
     */
   
public function getExitCode()
    {
        if (!
$this->enhanceSigchildCompatibility && $this->isSigchildEnabled()) {
            throw new
RuntimeException('This PHP has been compiled with --enable-sigchild. You must use setEnhanceSigchildCompatibility() to use this method.');
        }

       
$this->updateStatus(false);

        return
$this->exitcode;
    }

   
/**
     * Returns a string representation for the exit code returned by the process.
     *
     * This method relies on the Unix exit code status standardization
     * and might not be relevant for other operating systems.
     *
     * @return string|null A string representation for the exit status code, null if the Process is not terminated
     *
     * @see http://tldp.org/LDP/abs/html/exitcodes.html
     * @see http://en.wikipedia.org/wiki/Unix_signal
     */
   
public function getExitCodeText()
    {
        if (
null === $exitcode = $this->getExitCode()) {
            return
null;
        }

        return isset(
self::$exitCodes[$exitcode]) ? self::$exitCodes[$exitcode] : 'Unknown error';
    }

   
/**
     * Checks if the process ended successfully.
     *
     * @return bool true if the process ended successfully, false otherwise
     */
   
public function isSuccessful()
    {
        return
0 === $this->getExitCode();
    }

   
/**
     * Returns true if the child process has been terminated by an uncaught signal.
     *
     * It always returns false on Windows.
     *
     * @return bool
     *
     * @throws RuntimeException In case --enable-sigchild is activated
     * @throws LogicException   In case the process is not terminated
     */
   
public function hasBeenSignaled()
    {
       
$this->requireProcessIsTerminated(__FUNCTION__);

        if (!
$this->enhanceSigchildCompatibility && $this->isSigchildEnabled()) {
            throw new
RuntimeException('This PHP has been compiled with --enable-sigchild. Term signal can not be retrieved.');
        }

        return
$this->processInformation['signaled'];
    }

   
/**
     * Returns the number of the signal that caused the child process to terminate its execution.
     *
     * It is only meaningful if hasBeenSignaled() returns true.
     *
     * @return int
     *
     * @throws RuntimeException In case --enable-sigchild is activated
     * @throws LogicException   In case the process is not terminated
     */
   
public function getTermSignal()
    {
       
$this->requireProcessIsTerminated(__FUNCTION__);

        if (
$this->isSigchildEnabled() && (!$this->enhanceSigchildCompatibility || -1 === $this->processInformation['termsig'])) {
            throw new
RuntimeException('This PHP has been compiled with --enable-sigchild. Term signal can not be retrieved.');
        }

        return
$this->processInformation['termsig'];
    }

   
/**
     * Returns true if the child process has been stopped by a signal.
     *
     * It always returns false on Windows.
     *
     * @return bool
     *
     * @throws LogicException In case the process is not terminated
     */
   
public function hasBeenStopped()
    {
       
$this->requireProcessIsTerminated(__FUNCTION__);

        return
$this->processInformation['stopped'];
    }

   
/**
     * Returns the number of the signal that caused the child process to stop its execution.
     *
     * It is only meaningful if hasBeenStopped() returns true.
     *
     * @return int
     *
     * @throws LogicException In case the process is not terminated
     */
   
public function getStopSignal()
    {
       
$this->requireProcessIsTerminated(__FUNCTION__);

        return
$this->processInformation['stopsig'];
    }

   
/**
     * Checks if the process is currently running.
     *
     * @return bool true if the process is currently running, false otherwise
     */
   
public function isRunning()
    {
        if (
self::STATUS_STARTED !== $this->status) {
            return
false;
        }

       
$this->updateStatus(false);

        return
$this->processInformation['running'];
    }

   
/**
     * Checks if the process has been started with no regard to the current state.
     *
     * @return bool true if status is ready, false otherwise
     */
   
public function isStarted()
    {
        return
self::STATUS_READY != $this->status;
    }

   
/**
     * Checks if the process is terminated.
     *
     * @return bool true if process is terminated, false otherwise
     */
   
public function isTerminated()
    {
       
$this->updateStatus(false);

        return
self::STATUS_TERMINATED == $this->status;
    }

   
/**
     * Gets the process status.
     *
     * The status is one of: ready, started, terminated.
     *
     * @return string The current process status
     */
   
public function getStatus()
    {
       
$this->updateStatus(false);

        return
$this->status;
    }

   
/**
     * Stops the process.
     *
     * @param int|float $timeout The timeout in seconds
     * @param int       $signal  A POSIX signal to send in case the process has not stop at timeout, default is SIGKILL (9)
     *
     * @return int|null The exit-code of the process or null if it's not running
     */
   
public function stop($timeout = 10, $signal = null)
    {
       
$timeoutMicro = microtime(true) + $timeout;
        if (
$this->isRunning()) {
           
// given `SIGTERM` may not be defined and that `proc_terminate` uses the constant value and not the constant itself, we use the same here
           
$this->doSignal(15, false);
            do {
               
usleep(1000);
            } while (
$this->isRunning() && microtime(true) < $timeoutMicro);

            if (
$this->isRunning()) {
               
// Avoid exception here: process is supposed to be running, but it might have stopped just
                // after this line. In any case, let's silently discard the error, we cannot do anything.
               
$this->doSignal($signal ?: 9, false);
            }
        }

        if (
$this->isRunning()) {
            if (isset(
$this->fallbackStatus['pid'])) {
                unset(
$this->fallbackStatus['pid']);

                return
$this->stop(0, $signal);
            }
           
$this->close();
        }

        return
$this->exitcode;
    }

   
/**
     * Adds a line to the STDOUT stream.
     *
     * @internal
     *
     * @param string $line The line to append
     */
   
public function addOutput($line)
    {
       
$this->lastOutputTime = microtime(true);

       
fseek($this->stdout, 0, \SEEK_END);
       
fwrite($this->stdout, $line);
       
fseek($this->stdout, $this->incrementalOutputOffset);
    }

   
/**
     * Adds a line to the STDERR stream.
     *
     * @internal
     *
     * @param string $line The line to append
     */
   
public function addErrorOutput($line)
    {
       
$this->lastOutputTime = microtime(true);

       
fseek($this->stderr, 0, \SEEK_END);
       
fwrite($this->stderr, $line);
       
fseek($this->stderr, $this->incrementalErrorOutputOffset);
    }

   
/**
     * Gets the command line to be executed.
     *
     * @return string The command to execute
     */
   
public function getCommandLine()
    {
        return \
is_array($this->commandline) ? implode(' ', array_map([$this, 'escapeArgument'], $this->commandline)) : $this->commandline;
    }

   
/**
     * Sets the command line to be executed.
     *
     * @param string|array $commandline The command to execute
     *
     * @return $this
     */
   
public function setCommandLine($commandline)
    {
       
$this->commandline = $commandline;

        return
$this;
    }

   
/**
     * Gets the process timeout (max. runtime).
     *
     * @return float|null The timeout in seconds or null if it's disabled
     */
   
public function getTimeout()
    {
        return
$this->timeout;
    }

   
/**
     * Gets the process idle timeout (max. time since last output).
     *
     * @return float|null The timeout in seconds or null if it's disabled
     */
   
public function getIdleTimeout()
    {
        return
$this->idleTimeout;
    }

   
/**
     * Sets the process timeout (max. runtime) in seconds.
     *
     * To disable the timeout, set this value to null.
     *
     * @param int|float|null $timeout The timeout in seconds
     *
     * @return $this
     *
     * @throws InvalidArgumentException if the timeout is negative
     */
   
public function setTimeout($timeout)
    {
       
$this->timeout = $this->validateTimeout($timeout);

        return
$this;
    }

   
/**
     * Sets the process idle timeout (max. time since last output).
     *
     * To disable the timeout, set this value to null.
     *
     * @param int|float|null $timeout The timeout in seconds
     *
     * @return $this
     *
     * @throws LogicException           if the output is disabled
     * @throws InvalidArgumentException if the timeout is negative
     */
   
public function setIdleTimeout($timeout)
    {
        if (
null !== $timeout && $this->outputDisabled) {
            throw new
LogicException('Idle timeout can not be set while the output is disabled.');
        }

       
$this->idleTimeout = $this->validateTimeout($timeout);

        return
$this;
    }

   
/**
     * Enables or disables the TTY mode.
     *
     * @param bool $tty True to enabled and false to disable
     *
     * @return $this
     *
     * @throws RuntimeException In case the TTY mode is not supported
     */
   
public function setTty($tty)
    {
        if (
'\\' === \DIRECTORY_SEPARATOR && $tty) {
            throw new
RuntimeException('TTY mode is not supported on Windows platform.');
        }
        if (
$tty) {
            static
$isTtySupported;

            if (
null === $isTtySupported) {
               
$isTtySupported = (bool) @proc_open('echo 1 >/dev/null', [['file', '/dev/tty', 'r'], ['file', '/dev/tty', 'w'], ['file', '/dev/tty', 'w']], $pipes);
            }

            if (!
$isTtySupported) {
                throw new
RuntimeException('TTY mode requires /dev/tty to be read/writable.');
            }
        }

       
$this->tty = (bool) $tty;

        return
$this;
    }

   
/**
     * Checks if the TTY mode is enabled.
     *
     * @return bool true if the TTY mode is enabled, false otherwise
     */
   
public function isTty()
    {
        return
$this->tty;
    }

   
/**
     * Sets PTY mode.
     *
     * @param bool $bool
     *
     * @return $this
     */
   
public function setPty($bool)
    {
       
$this->pty = (bool) $bool;

        return
$this;
    }

   
/**
     * Returns PTY state.
     *
     * @return bool
     */
   
public function isPty()
    {
        return
$this->pty;
    }

   
/**
     * Gets the working directory.
     *
     * @return string|null The current working directory or null on failure
     */
   
public function getWorkingDirectory()
    {
        if (
null === $this->cwd) {
           
// getcwd() will return false if any one of the parent directories does not have
            // the readable or search mode set, even if the current directory does
           
return getcwd() ?: null;
        }

        return
$this->cwd;
    }

   
/**
     * Sets the current working directory.
     *
     * @param string $cwd The new working directory
     *
     * @return $this
     */
   
public function setWorkingDirectory($cwd)
    {
       
$this->cwd = $cwd;

        return
$this;
    }

   
/**
     * Gets the environment variables.
     *
     * @return array The current environment variables
     */
   
public function getEnv()
    {
        return
$this->env;
    }

   
/**
     * Sets the environment variables.
     *
     * Each environment variable value should be a string.
     * If it is an array, the variable is ignored.
     * If it is false or null, it will be removed when
     * env vars are otherwise inherited.
     *
     * That happens in PHP when 'argv' is registered into
     * the $_ENV array for instance.
     *
     * @param array $env The new environment variables
     *
     * @return $this
     */
   
public function setEnv(array $env)
    {
       
// Process can not handle env values that are arrays
       
$env = array_filter($env, function ($value) {
            return !\
is_array($value);
        });

       
$this->env = $env;

        return
$this;
    }

   
/**
     * Gets the Process input.
     *
     * @return resource|string|\Iterator|null The Process input
     */
   
public function getInput()
    {
        return
$this->input;
    }

   
/**
     * Sets the input.
     *
     * This content will be passed to the underlying process standard input.
     *
     * @param string|int|float|bool|resource|\Traversable|null $input The content
     *
     * @return $this
     *
     * @throws LogicException In case the process is running
     */
   
public function setInput($input)
    {
        if (
$this->isRunning()) {
            throw new
LogicException('Input can not be set while the process is running.');
        }

       
$this->input = ProcessUtils::validateInput(__METHOD__, $input);

        return
$this;
    }

   
/**
     * Gets the options for proc_open.
     *
     * @return array The current options
     *
     * @deprecated since version 3.3, to be removed in 4.0.
     */
   
public function getOptions()
    {
        @
trigger_error(sprintf('The %s() method is deprecated since Symfony 3.3 and will be removed in 4.0.', __METHOD__), \E_USER_DEPRECATED);

        return
$this->options;
    }

   
/**
     * Sets the options for proc_open.
     *
     * @param array $options The new options
     *
     * @return $this
     *
     * @deprecated since version 3.3, to be removed in 4.0.
     */
   
public function setOptions(array $options)
    {
        @
trigger_error(sprintf('The %s() method is deprecated since Symfony 3.3 and will be removed in 4.0.', __METHOD__), \E_USER_DEPRECATED);

       
$this->options = $options;

        return
$this;
    }

   
/**
     * Gets whether or not Windows compatibility is enabled.
     *
     * This is true by default.
     *
     * @return bool
     *
     * @deprecated since version 3.3, to be removed in 4.0. Enhanced Windows compatibility will always be enabled.
     */
   
public function getEnhanceWindowsCompatibility()
    {
        @
trigger_error(sprintf('The %s() method is deprecated since Symfony 3.3 and will be removed in 4.0. Enhanced Windows compatibility will always be enabled.', __METHOD__), \E_USER_DEPRECATED);

        return
$this->enhanceWindowsCompatibility;
    }

   
/**
     * Sets whether or not Windows compatibility is enabled.
     *
     * @param bool $enhance
     *
     * @return $this
     *
     * @deprecated since version 3.3, to be removed in 4.0. Enhanced Windows compatibility will always be enabled.
     */
   
public function setEnhanceWindowsCompatibility($enhance)
    {
        @
trigger_error(sprintf('The %s() method is deprecated since Symfony 3.3 and will be removed in 4.0. Enhanced Windows compatibility will always be enabled.', __METHOD__), \E_USER_DEPRECATED);

       
$this->enhanceWindowsCompatibility = (bool) $enhance;

        return
$this;
    }

   
/**
     * Returns whether sigchild compatibility mode is activated or not.
     *
     * @return bool
     *
     * @deprecated since version 3.3, to be removed in 4.0. Sigchild compatibility will always be enabled.
     */
   
public function getEnhanceSigchildCompatibility()
    {
        @
trigger_error(sprintf('The %s() method is deprecated since Symfony 3.3 and will be removed in 4.0. Sigchild compatibility will always be enabled.', __METHOD__), \E_USER_DEPRECATED);

        return
$this->enhanceSigchildCompatibility;
    }

   
/**
     * Activates sigchild compatibility mode.
     *
     * Sigchild compatibility mode is required to get the exit code and
     * determine the success of a process when PHP has been compiled with
     * the --enable-sigchild option
     *
     * @param bool $enhance
     *
     * @return $this
     *
     * @deprecated since version 3.3, to be removed in 4.0.
     */
   
public function setEnhanceSigchildCompatibility($enhance)
    {
        @
trigger_error(sprintf('The %s() method is deprecated since Symfony 3.3 and will be removed in 4.0. Sigchild compatibility will always be enabled.', __METHOD__), \E_USER_DEPRECATED);

       
$this->enhanceSigchildCompatibility = (bool) $enhance;

        return
$this;
    }

   
/**
     * Sets whether environment variables will be inherited or not.
     *
     * @param bool $inheritEnv
     *
     * @return $this
     */
   
public function inheritEnvironmentVariables($inheritEnv = true)
    {
        if (!
$inheritEnv) {
            @
trigger_error('Not inheriting environment variables is deprecated since Symfony 3.3 and will always happen in 4.0. Set "Process::inheritEnvironmentVariables()" to true instead.', \E_USER_DEPRECATED);
        }

       
$this->inheritEnv = (bool) $inheritEnv;

        return
$this;
    }

   
/**
     * Returns whether environment variables will be inherited or not.
     *
     * @return bool
     *
     * @deprecated since version 3.3, to be removed in 4.0. Environment variables will always be inherited.
     */
   
public function areEnvironmentVariablesInherited()
    {
        @
trigger_error(sprintf('The %s() method is deprecated since Symfony 3.3 and will be removed in 4.0. Environment variables will always be inherited.', __METHOD__), \E_USER_DEPRECATED);

        return
$this->inheritEnv;
    }

   
/**
     * Performs a check between the timeout definition and the time the process started.
     *
     * In case you run a background process (with the start method), you should
     * trigger this method regularly to ensure the process timeout
     *
     * @throws ProcessTimedOutException In case the timeout was reached
     */
   
public function checkTimeout()
    {
        if (
self::STATUS_STARTED !== $this->status) {
            return;
        }

        if (
null !== $this->timeout && $this->timeout < microtime(true) - $this->starttime) {
           
$this->stop(0);

            throw new
ProcessTimedOutException($this, ProcessTimedOutException::TYPE_GENERAL);
        }

        if (
null !== $this->idleTimeout && $this->idleTimeout < microtime(true) - $this->lastOutputTime) {
           
$this->stop(0);

            throw new
ProcessTimedOutException($this, ProcessTimedOutException::TYPE_IDLE);
        }
    }

   
/**
     * Returns whether PTY is supported on the current operating system.
     *
     * @return bool
     */
   
public static function isPtySupported()
    {
        static
$result;

        if (
null !== $result) {
            return
$result;
        }

        if (
'\\' === \DIRECTORY_SEPARATOR) {
            return
$result = false;
        }

        return
$result = (bool) @proc_open('echo 1 >/dev/null', [['pty'], ['pty'], ['pty']], $pipes);
    }

   
/**
     * Creates the descriptors needed by the proc_open.
     *
     * @return array
     */
   
private function getDescriptors()
    {
        if (
$this->input instanceof \Iterator) {
           
$this->input->rewind();
        }
        if (
'\\' === \DIRECTORY_SEPARATOR) {
           
$this->processPipes = new WindowsPipes($this->input, !$this->outputDisabled || $this->hasCallback);
        } else {
           
$this->processPipes = new UnixPipes($this->isTty(), $this->isPty(), $this->input, !$this->outputDisabled || $this->hasCallback);
        }

        return
$this->processPipes->getDescriptors();
    }

   
/**
     * Builds up the callback used by wait().
     *
     * The callbacks adds all occurred output to the specific buffer and calls
     * the user callback (if present) with the received output.
     *
     * @param callable|null $callback The user defined PHP callback
     *
     * @return \Closure A PHP closure
     */
   
protected function buildCallback(callable $callback = null)
    {
        if (
$this->outputDisabled) {
            return function (
$type, $data) use ($callback) {
                if (
null !== $callback) {
                    \
call_user_func($callback, $type, $data);
                }
            };
        }

       
$out = self::OUT;

        return function (
$type, $data) use ($callback, $out) {
            if (
$out == $type) {
               
$this->addOutput($data);
            } else {
               
$this->addErrorOutput($data);
            }

            if (
null !== $callback) {
                \
call_user_func($callback, $type, $data);
            }
        };
    }

   
/**
     * Updates the status of the process, reads pipes.
     *
     * @param bool $blocking Whether to use a blocking read call
     */
   
protected function updateStatus($blocking)
    {
        if (
self::STATUS_STARTED !== $this->status) {
            return;
        }

       
$this->processInformation = proc_get_status($this->process);
       
$running = $this->processInformation['running'];

       
$this->readPipes($running && $blocking, '\\' !== \DIRECTORY_SEPARATOR || !$running);

        if (
$this->fallbackStatus && $this->enhanceSigchildCompatibility && $this->isSigchildEnabled()) {
           
$this->processInformation = $this->fallbackStatus + $this->processInformation;
        }

        if (!
$running) {
           
$this->close();
        }
    }

   
/**
     * Returns whether PHP has been compiled with the '--enable-sigchild' option or not.
     *
     * @return bool
     */
   
protected function isSigchildEnabled()
    {
        if (
null !== self::$sigchild) {
            return
self::$sigchild;
        }

        if (!\
function_exists('phpinfo') || \defined('HHVM_VERSION')) {
            return
self::$sigchild = false;
        }

       
ob_start();
       
phpinfo(\INFO_GENERAL);

        return
self::$sigchild = false !== strpos(ob_get_clean(), '--enable-sigchild');
    }

   
/**
     * Reads pipes for the freshest output.
     *
     * @param string $caller   The name of the method that needs fresh outputs
     * @param bool   $blocking Whether to use blocking calls or not
     *
     * @throws LogicException in case output has been disabled or process is not started
     */
   
private function readPipesForOutput($caller, $blocking = false)
    {
        if (
$this->outputDisabled) {
            throw new
LogicException('Output has been disabled.');
        }

       
$this->requireProcessIsStarted($caller);

       
$this->updateStatus($blocking);
    }

   
/**
     * Validates and returns the filtered timeout.
     *
     * @param int|float|null $timeout
     *
     * @return float|null
     *
     * @throws InvalidArgumentException if the given timeout is a negative number
     */
   
private function validateTimeout($timeout)
    {
       
$timeout = (float) $timeout;

        if (
0.0 === $timeout) {
           
$timeout = null;
        } elseif (
$timeout < 0) {
            throw new
InvalidArgumentException('The timeout value must be a valid positive integer or float number.');
        }

        return
$timeout;
    }

   
/**
     * Reads pipes, executes callback.
     *
     * @param bool $blocking Whether to use blocking calls or not
     * @param bool $close    Whether to close file handles or not
     */
   
private function readPipes($blocking, $close)
    {
       
$result = $this->processPipes->readAndWrite($blocking, $close);

       
$callback = $this->callback;
        foreach (
$result as $type => $data) {
            if (
3 !== $type) {
               
$callback(self::STDOUT === $type ? self::OUT : self::ERR, $data);
            } elseif (!isset(
$this->fallbackStatus['signaled'])) {
               
$this->fallbackStatus['exitcode'] = (int) $data;
            }
        }
    }

   
/**
     * Closes process resource, closes file handles, sets the exitcode.
     *
     * @return int The exitcode
     */
   
private function close()
    {
       
$this->processPipes->close();
        if (\
is_resource($this->process)) {
           
proc_close($this->process);
        }
       
$this->exitcode = $this->processInformation['exitcode'];
       
$this->status = self::STATUS_TERMINATED;

        if (-
1 === $this->exitcode) {
            if (
$this->processInformation['signaled'] && 0 < $this->processInformation['termsig']) {
               
// if process has been signaled, no exitcode but a valid termsig, apply Unix convention
               
$this->exitcode = 128 + $this->processInformation['termsig'];
            } elseif (
$this->enhanceSigchildCompatibility && $this->isSigchildEnabled()) {
               
$this->processInformation['signaled'] = true;
               
$this->processInformation['termsig'] = -1;
            }
        }

       
// Free memory from self-reference callback created by buildCallback
        // Doing so in other contexts like __destruct or by garbage collector is ineffective
        // Now pipes are closed, so the callback is no longer necessary
       
$this->callback = null;

        return
$this->exitcode;
    }

   
/**
     * Resets data related to the latest run of the process.
     */
   
private function resetProcessData()
    {
       
$this->starttime = null;
       
$this->callback = null;
       
$this->exitcode = null;
       
$this->fallbackStatus = [];
       
$this->processInformation = null;
       
$this->stdout = fopen('php://temp/maxmemory:'.(1024 * 1024), 'w+b');
       
$this->stderr = fopen('php://temp/maxmemory:'.(1024 * 1024), 'w+b');
       
$this->process = null;
       
$this->latestSignal = null;
       
$this->status = self::STATUS_READY;
       
$this->incrementalOutputOffset = 0;
       
$this->incrementalErrorOutputOffset = 0;
    }

   
/**
     * Sends a POSIX signal to the process.
     *
     * @param int  $signal         A valid POSIX signal (see https://php.net/pcntl.constants)
     * @param bool $throwException Whether to throw exception in case signal failed
     *
     * @return bool True if the signal was sent successfully, false otherwise
     *
     * @throws LogicException   In case the process is not running
     * @throws RuntimeException In case --enable-sigchild is activated and the process can't be killed
     * @throws RuntimeException In case of failure
     */
   
private function doSignal($signal, $throwException)
    {
        if (
null === $pid = $this->getPid()) {
            if (
$throwException) {
                throw new
LogicException('Can not send signal on a non running process.');
            }

            return
false;
        }

        if (
'\\' === \DIRECTORY_SEPARATOR) {
           
exec(sprintf('taskkill /F /T /PID %d 2>&1', $pid), $output, $exitCode);
            if (
$exitCode && $this->isRunning()) {
                if (
$throwException) {
                    throw new
RuntimeException(sprintf('Unable to kill the process (%s).', implode(' ', $output)));
                }

                return
false;
            }
        } else {
            if (!
$this->enhanceSigchildCompatibility || !$this->isSigchildEnabled()) {
               
$ok = @proc_terminate($this->process, $signal);
            } elseif (\
function_exists('posix_kill')) {
               
$ok = @posix_kill($pid, $signal);
            } elseif (
$ok = proc_open(sprintf('kill -%d %d', $signal, $pid), [2 => ['pipe', 'w']], $pipes)) {
               
$ok = false === fgets($pipes[2]);
            }
            if (!
$ok) {
                if (
$throwException) {
                    throw new
RuntimeException(sprintf('Error while sending signal `%s`.', $signal));
                }

                return
false;
            }
        }

       
$this->latestSignal = (int) $signal;
       
$this->fallbackStatus['signaled'] = true;
       
$this->fallbackStatus['exitcode'] = -1;
       
$this->fallbackStatus['termsig'] = $this->latestSignal;

        return
true;
    }

    private function
prepareWindowsCommandLine($cmd, array &$env)
    {
       
$uid = uniqid('', true);
       
$varCount = 0;
       
$varCache = [];
       
$cmd = preg_replace_callback(
           
'/"(?:(
                [^"%!^]*+
                (?:
                    (?: !LF! | "(?:\^[%!^])?+" )
                    [^"%!^]*+
                )++
            ) | [^"]*+ )"/x'
,
            function (
$m) use (&$env, &$varCache, &$varCount, $uid) {
                if (!isset(
$m[1])) {
                    return
$m[0];
                }
                if (isset(
$varCache[$m[0]])) {
                    return
$varCache[$m[0]];
                }
                if (
false !== strpos($value = $m[1], "\0")) {
                   
$value = str_replace("\0", '?', $value);
                }
                if (
false === strpbrk($value, "\"%!\n")) {
                    return
'"'.$value.'"';
                }

               
$value = str_replace(['!LF!', '"^!"', '"^%"', '"^^"', '""'], ["\n", '!', '%', '^', '"'], $value);
               
$value = '"'.preg_replace('/(\\\\*)"/', '$1$1\\"', $value).'"';
               
$var = $uid.++$varCount;

               
$env[$var] = $value;

                return
$varCache[$m[0]] = '!'.$var.'!';
            },
           
$cmd
       
);

       
$cmd = 'cmd /V:ON /E:ON /D /C ('.str_replace("\n", ' ', $cmd).')';
        foreach (
$this->processPipes->getFiles() as $offset => $filename) {
           
$cmd .= ' '.$offset.'>"'.$filename.'"';
        }

        return
$cmd;
    }

   
/**
     * Ensures the process is running or terminated, throws a LogicException if the process has a not started.
     *
     * @param string $functionName The function name that was called
     *
     * @throws LogicException if the process has not run
     */
   
private function requireProcessIsStarted($functionName)
    {
        if (!
$this->isStarted()) {
            throw new
LogicException(sprintf('Process must be started before calling "%s()".', $functionName));
        }
    }

   
/**
     * Ensures the process is terminated, throws a LogicException if the process has a status different than `terminated`.
     *
     * @param string $functionName The function name that was called
     *
     * @throws LogicException if the process is not yet terminated
     */
   
private function requireProcessIsTerminated($functionName)
    {
        if (!
$this->isTerminated()) {
            throw new
LogicException(sprintf('Process must be terminated before calling "%s()".', $functionName));
        }
    }

   
/**
     * Escapes a string to be used as a shell argument.
     *
     * @param string $argument The argument that will be escaped
     *
     * @return string The escaped argument
     */
   
private function escapeArgument($argument)
    {
        if (
'\\' !== \DIRECTORY_SEPARATOR) {
            return
"'".str_replace("'", "'\\''", $argument)."'";
        }
        if (
'' === $argument = (string) $argument) {
            return
'""';
        }
        if (
false !== strpos($argument, "\0")) {
           
$argument = str_replace("\0", '?', $argument);
        }
        if (!
preg_match('/[\/()%!^"<>&|\s]/', $argument)) {
            return
$argument;
        }
       
$argument = preg_replace('/(\\\\+)$/', '$1$1', $argument);

        return
'"'.str_replace(['"', '^', '%', '!', "\n"], ['""', '"^^"', '"^%"', '"^!"', '!LF!'], $argument).'"';
    }

    private function
getDefaultEnv()
    {
       
$env = [];

        foreach (
$_SERVER as $k => $v) {
            if (\
is_string($v) && false !== $v = getenv($k)) {
               
$env[$k] = $v;
            }
        }

        foreach (
$_ENV as $k => $v) {
            if (\
is_string($v)) {
               
$env[$k] = $v;
            }
        }

        return
$env;
    }
}