/**
 * Execute a shell command, with time and memory limits mirrored from the PHP
 * configuration if supported.
 *
 * @param string|string[] $cmd If string, a properly shell-escaped command line,
 *   or an array of unescaped arguments, in which case each value will be escaped
 *   Example:   [ 'convert', '-font', 'font name' ] would produce "'convert' '-font' 'font name'"
 * @param null|mixed &$retval Optional, will receive the program's exit code.
 *   (non-zero is usually failure). If there is an error from
 *   read, select, or proc_open(), this will be set to -1.
 * @param array $environ Optional environment variables which should be
 *   added to the executed command environment.
 * @param array $limits Optional array with limits(filesize, memory, time, walltime)
 *   this overwrites the global wgMaxShell* limits.
 * @param array $options Array of options:
 *   - duplicateStderr: Set this to true to duplicate stderr to stdout,
 *     including errors from limit.sh
 *   - profileMethod: By default this function will profile based on the calling
 *     method. Set this to a string for an alternative method to profile from
 *
 * @return string Collected stdout as a string
 */
function wfShellExec($cmd, &$retval = null, $environ = array(), $limits = array(), $options = array())
{
    global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime, $wgMaxShellWallClockTime, $wgShellCgroup;
    $disabled = wfShellExecDisabled();
    if ($disabled) {
        $retval = 1;
        return $disabled == 'safemode' ? 'Unable to run external programs in safe mode.' : 'Unable to run external programs, proc_open() is disabled.';
    }
    $includeStderr = isset($options['duplicateStderr']) && $options['duplicateStderr'];
    $profileMethod = isset($options['profileMethod']) ? $options['profileMethod'] : wfGetCaller();
    wfInitShellLocale();
    $envcmd = '';
    foreach ($environ as $k => $v) {
        if (wfIsWindows()) {
            /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
             * appear in the environment variable, so we must use carat escaping as documented in
             * http://technet.microsoft.com/en-us/library/cc723564.aspx
             * Note however that the quote isn't listed there, but is needed, and the parentheses
             * are listed there but doesn't appear to need it.
             */
            $envcmd .= "set {$k}=" . preg_replace('/([&|()<>^"])/', '^\\1', $v) . '&& ';
        } else {
            /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
             * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
             */
            $envcmd .= "{$k}=" . escapeshellarg($v) . ' ';
        }
    }
    if (is_array($cmd)) {
        $cmd = wfEscapeShellArg($cmd);
    }
    $cmd = $envcmd . $cmd;
    $useLogPipe = false;
    if (is_executable('/bin/bash')) {
        $time = intval(isset($limits['time']) ? $limits['time'] : $wgMaxShellTime);
        if (isset($limits['walltime'])) {
            $wallTime = intval($limits['walltime']);
        } elseif (isset($limits['time'])) {
            $wallTime = $time;
        } else {
            $wallTime = intval($wgMaxShellWallClockTime);
        }
        $mem = intval(isset($limits['memory']) ? $limits['memory'] : $wgMaxShellMemory);
        $filesize = intval(isset($limits['filesize']) ? $limits['filesize'] : $wgMaxShellFileSize);
        if ($time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0) {
            $cmd = '/bin/bash ' . escapeshellarg("{$IP}/includes/limit.sh") . ' ' . escapeshellarg($cmd) . ' ' . escapeshellarg("MW_INCLUDE_STDERR=" . ($includeStderr ? '1' : '') . ';' . "MW_CPU_LIMIT={$time}; " . 'MW_CGROUP=' . escapeshellarg($wgShellCgroup) . '; ' . "MW_MEM_LIMIT={$mem}; " . "MW_FILE_SIZE_LIMIT={$filesize}; " . "MW_WALL_CLOCK_LIMIT={$wallTime}; " . "MW_USE_LOG_PIPE=yes");
            $useLogPipe = true;
        } elseif ($includeStderr) {
            $cmd .= ' 2>&1';
        }
    } elseif ($includeStderr) {
        $cmd .= ' 2>&1';
    }
    wfDebug("wfShellExec: {$cmd}\n");
    $desc = array(0 => array('file', 'php://stdin', 'r'), 1 => array('pipe', 'w'), 2 => array('file', 'php://stderr', 'w'));
    if ($useLogPipe) {
        $desc[3] = array('pipe', 'w');
    }
    $pipes = null;
    $scoped = Profiler::instance()->scopedProfileIn(__FUNCTION__ . '-' . $profileMethod);
    $proc = proc_open($cmd, $desc, $pipes);
    if (!$proc) {
        wfDebugLog('exec', "proc_open() failed: {$cmd}");
        $retval = -1;
        return '';
    }
    $outBuffer = $logBuffer = '';
    $emptyArray = array();
    $status = false;
    $logMsg = false;
    // According to the documentation, it is possible for stream_select()
    // to fail due to EINTR. I haven't managed to induce this in testing
    // despite sending various signals. If it did happen, the error
    // message would take the form:
    //
    // stream_select(): unable to select [4]: Interrupted system call (max_fd=5)
    //
    // where [4] is the value of the macro EINTR and "Interrupted system
//.........这里部分代码省略.........

/**
 * Execute a shell command, with time and memory limits mirrored from the PHP
 * configuration if supported.
 * @param string $cmd Command line, properly escaped for shell.
 * @param &$retval null|Mixed optional, will receive the program's exit code.
 *                 (non-zero is usually failure)
 * @param array $environ optional environment variables which should be
 *                 added to the executed command environment.
 * @param array $limits optional array with limits(filesize, memory, time, walltime)
 *                 this overwrites the global wgShellMax* limits.
 * @return string collected stdout as a string (trailing newlines stripped)
 */
function wfShellExec($cmd, &$retval = null, $environ = array(), $limits = array())
{
    global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime, $wgMaxShellWallClockTime, $wgShellCgroup;
    $disabled = wfShellExecDisabled();
    if ($disabled) {
        $retval = 1;
        return $disabled == 'safemode' ? 'Unable to run external programs in safe mode.' : 'Unable to run external programs, passthru() is disabled.';
    }
    wfInitShellLocale();
    $envcmd = '';
    foreach ($environ as $k => $v) {
        if (wfIsWindows()) {
            /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
             * appear in the environment variable, so we must use carat escaping as documented in
             * http://technet.microsoft.com/en-us/library/cc723564.aspx
             * Note however that the quote isn't listed there, but is needed, and the parentheses
             * are listed there but doesn't appear to need it.
             */
            $envcmd .= "set {$k}=" . preg_replace('/([&|()<>^"])/', '^\\1', $v) . '&& ';
        } else {
            /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
             * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
             */
            $envcmd .= "{$k}=" . escapeshellarg($v) . ' ';
        }
    }
    $cmd = $envcmd . $cmd;
    if (php_uname('s') == 'Linux') {
        $time = intval(isset($limits['time']) ? $limits['time'] : $wgMaxShellTime);
        if (isset($limits['walltime'])) {
            $wallTime = intval($limits['walltime']);
        } elseif (isset($limits['time'])) {
            $wallTime = $time;
        } else {
            $wallTime = intval($wgMaxShellWallClockTime);
        }
        $mem = intval(isset($limits['memory']) ? $limits['memory'] : $wgMaxShellMemory);
        $filesize = intval(isset($limits['filesize']) ? $limits['filesize'] : $wgMaxShellFileSize);
        if ($time > 0 || $mem > 0 || $filesize > 0 || $wallTime > 0) {
            $cmd = '/bin/bash ' . escapeshellarg("{$IP}/includes/limit.sh") . ' ' . escapeshellarg($cmd) . ' ' . escapeshellarg("MW_CPU_LIMIT={$time}; " . 'MW_CGROUP=' . escapeshellarg($wgShellCgroup) . '; ' . "MW_MEM_LIMIT={$mem}; " . "MW_FILE_SIZE_LIMIT={$filesize}; " . "MW_WALL_CLOCK_LIMIT={$wallTime}");
        }
    }
    wfDebug("wfShellExec: {$cmd}\n");
    $retval = 1;
    // error by default?
    ob_start();
    passthru($cmd, $retval);
    $output = ob_get_contents();
    ob_end_clean();
    if ($retval == 127) {
        wfDebugLog('exec', "Possibly missing executable file: {$cmd}\n");
    }
    return $output;
}

/**
 * Execute a shell command, with time and memory limits mirrored from the PHP
 * configuration if supported.
 * @param $cmd String Command line, properly escaped for shell.
 * @param &$retval optional, will receive the program's exit code.
 *                 (non-zero is usually failure)
 * @param $environ Array optional environment variables which should be
 *                 added to the executed command environment.
 * @return collected stdout as a string (trailing newlines stripped)
 */
function wfShellExec($cmd, &$retval = null, $environ = array())
{
    global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
    static $disabled;
    if (is_null($disabled)) {
        $disabled = false;
        if (wfIniGetBool('safe_mode')) {
            wfDebug("wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n");
            $disabled = 'safemode';
        } else {
            $functions = explode(',', ini_get('disable_functions'));
            $functions = array_map('trim', $functions);
            $functions = array_map('strtolower', $functions);
            if (in_array('passthru', $functions)) {
                wfDebug("passthru is in disabled_functions\n");
                $disabled = 'passthru';
            }
        }
    }
    if ($disabled) {
        $retval = 1;
        return $disabled == 'safemode' ? 'Unable to run external programs in safe mode.' : 'Unable to run external programs, passthru() is disabled.';
    }
    wfInitShellLocale();
    $envcmd = '';
    foreach ($environ as $k => $v) {
        if (wfIsWindows()) {
            /* Surrounding a set in quotes (method used by wfEscapeShellArg) makes the quotes themselves
             * appear in the environment variable, so we must use carat escaping as documented in
             * http://technet.microsoft.com/en-us/library/cc723564.aspx
             * Note however that the quote isn't listed there, but is needed, and the parentheses
             * are listed there but doesn't appear to need it.
             */
            $envcmd .= "set {$k}=" . preg_replace('/([&|()<>^"])/', '^\\1', $v) . '&& ';
        } else {
            /* Assume this is a POSIX shell, thus required to accept variable assignments before the command
             * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01
             */
            $envcmd .= "{$k}=" . escapeshellarg($v) . ' ';
        }
    }
    $cmd = $envcmd . $cmd;
    if (wfIsWindows()) {
        if (version_compare(PHP_VERSION, '5.3.0', '<') && (version_compare(PHP_VERSION, '5.2.1', '>=') || php_uname('s') == 'Windows NT')) {
            # Hack to work around PHP's flawed invocation of cmd.exe
            # http://news.php.net/php.internals/21796
            # Windows 9x doesn't accept any kind of quotes
            $cmd = '"' . $cmd . '"';
        }
    } elseif (php_uname('s') == 'Linux') {
        $time = intval($wgMaxShellTime);
        $mem = intval($wgMaxShellMemory);
        $filesize = intval($wgMaxShellFileSize);
        if ($time > 0 && $mem > 0) {
            $script = "{$IP}/bin/ulimit4.sh";
            if (is_executable($script)) {
                $cmd = '/bin/bash ' . escapeshellarg($script) . " {$time} {$mem} {$filesize} " . escapeshellarg($cmd);
            }
        }
    }
    wfDebug("wfShellExec: {$cmd}\n");
    $retval = 1;
    // error by default?
    ob_start();
    passthru($cmd, $retval);
    $output = ob_get_contents();
    ob_end_clean();
    if ($retval == 127) {
        wfDebugLog('exec', "Possibly missing executable file: {$cmd}\n");
    }
    return $output;
}

/**
 * Execute a shell command, with time and memory limits mirrored from the PHP
 * configuration if supported.
 * @param $cmd Command line, properly escaped for shell.
 * @param &$retval optional, will receive the program's exit code.
 *                 (non-zero is usually failure)
 * @return collected stdout as a string (trailing newlines stripped)
 */
function wfShellExec($cmd, &$retval = null)
{
    global $IP, $wgMaxShellMemory, $wgMaxShellFileSize, $wgMaxShellTime;
    static $disabled;
    if (is_null($disabled)) {
        $disabled = false;
        if (wfIniGetBool('safe_mode')) {
            wfDebug("wfShellExec can't run in safe_mode, PHP's exec functions are too broken.\n");
            $disabled = true;
        }
        $functions = explode(',', ini_get('disable_functions'));
        $functions = array_map('trim', $functions);
        $functions = array_map('strtolower', $functions);
        if (in_array('passthru', $functions)) {
            wfDebug("passthru is in disabled_functions\n");
            $disabled = true;
        }
    }
    if ($disabled) {
        $retval = 1;
        return "Unable to run external programs in safe mode.";
    }
    wfInitShellLocale();
    if (php_uname('s') == 'Linux') {
        $time = intval($wgMaxShellTime);
        $mem = intval($wgMaxShellMemory);
        $filesize = intval($wgMaxShellFileSize);
        if ($time > 0 && $mem > 0) {
            $script = "{$IP}/bin/ulimit4.sh";
            if (is_executable($script)) {
                $cmd = escapeshellarg($script) . " {$time} {$mem} {$filesize} " . escapeshellarg($cmd);
            }
        }
    } elseif (php_uname('s') == 'Windows NT') {
        # This is a hack to work around PHP's flawed invocation of cmd.exe
        # http://news.php.net/php.internals/21796
        $cmd = '"' . $cmd . '"';
    }
    wfDebug("wfShellExec: {$cmd}\n");
    $retval = 1;
    // error by default?
    ob_start();
    passthru($cmd, $retval);
    $output = ob_get_contents();
    ob_end_clean();
    if ($retval == 127) {
        wfDebugLog('exec', "Possibly missing executable file: {$cmd}\n");
    }
    return $output;
}