Test File or Folder for Dangerous PHP Functions

dangerous_functions.php

<?php
/**
 * dangerous_functions.php
 * Perry Holden <perry.holden@gmail.com>
 *
 * Usage: php dangerous_functions.php [type: folder|file] [folder_or_filename]
 * Example: php dangerous_functions.php folder vendor/businessname/module-name
 */

if (!isset($argv[1])) {
    echo "Missing action ('folder' or 'file')\n";
    die();
}

if (!isset($argv[2])) {
    echo "Missing folder name or file name\n";
    die();
}

$dangerousFunctions = new DangerousFunctions($argv[1], $argv[2]);
$dangerousFunctions->execute();

class DangerousFunctions
{
    /**
     * Complete list of dangerous functions for which we will scan
     *
     * @var array
     */
    protected $functions = [
        'apache_child_terminate',
        'apache_get_modules',
        'apache_note',
        'apache_setenv',
        'define_syslog_variables',
        'disk_free_space',
        'disk_total_space',
        'diskfreespace',
        'dl',
        'escapeshellarg',
        'escapeshellcmd',
        'exec',
        'extract',
        'get_cfg_var',
        'get_current_user',
        'getcwd',
        'getenv',
        'getlastmo',
        'getmygid',
        'getmyinode',
        'getmypid',
        'getmyuid',
        'ini_restore',
        'ini_set',
        'passthru',
        'pcntl_alarm',
        'pcntl_exec',
        'pcntl_fork',
        'pcntl_get_last_error',
        'pcntl_getpriority',
        'pcntl_setpriority',
        'pcntl_signal',
        'pcntl_signal_dispatch',
        'pcntl_sigprocmask',
        'pcntl_sigtimedwait',
        'pcntl_sigwaitinfo',
        'pcntl_strerrorp',
        'pcntl_wait',
        'pcntl_waitpid',
        'pcntl_wexitstatus',
        'pcntl_wifexited',
        'pcntl_wifsignaled',
        'pcntl_wifstopped',
        'pcntl_wstopsig',
        'pcntl_wtermsig',
        'php_uname',
        'phpinfo',
        'popen',
        'posix_getlogin',
        'posix_getpwuid',
        'posix_kill',
        'posix_mkfifo',
        'posix_setpgid',
        'posix_setsid',
        'posix_setuid',
        'posix_ttyname',
        'posix_uname',
        'posixc',
        'proc_close',
        'proc_get_status',
        'proc_nice',
        'proc_open',
        'proc_terminate',
        'ps_aux',
        'putenv',
        'readlink',
        'runkit_function_rename',
        'shell_exec',
        'show_source',
        'symlink',
        'syslog',
        'system',
    ];

    /**
     * Folders that this script will ignore and not process
     *
     * @var array
     */
    protected $foldersToIgnore = [
        '.',
        '..',
        '.git',
		'.idea'
    ];

    /**
     * Action: either 'folder' or 'file'
     *
     * @var string
     */
    protected $action;

    /**
     * Name of the folder or file
     *
     * @var string
     */
    protected $name;

    /**
     * @param string $action
     * @param string $name
     */
    public function __construct($action, $name)
    {
        $this->action = $action;
        $this->name = $name;
    }

    /**
     * Main action of script
     */
    public function execute()
    {
        if ($this->action == 'folder') {
            // If folder, loop through files in folder and test individually
			if ($allFiles = $this->getAllFiles($this->name)) {
                foreach ($allFiles as $fileToCheck) {
                    if (substr($fileToCheck, -3) === 'php') {
						$this->outputFileInfo($fileToCheck);
                    }
                }
            } else {
                echo "Folder is empty\n";
            }
			// If file, test directly
        } else if ($this->action == 'file') {
            $this->outputFileInfo($this->name);
        } else {
            echo "Invalid action: $this->action\n";
        }
    }

    /**
     * Outputs all dangerous methods in the specified file
     *
     * @param string $filename
     */
    protected function outputFileInfo($filename)
    {
        if ($file = fopen($filename, 'r')) {
            $count = 1;
            while (($line = fgets($file)) !== false) {
                foreach ($this->functions as $function) {
                    if (preg_match("/$function\(/", $line)) {
                        echo "$filename($count): $function\n";
                    }
                }
                $count++;
            }
            fclose($file);
        } else {
            echo "Invalid filename: $file\n";
        }
    }

    /**
     * Gets all the files in the folder and returns them as an array (this is a recursive method)
     *
     * @param string $folder
     * @param array $results
     * @return array
     */
    protected function getAllFiles($folder, &$results = []) {
        $files = scandir($folder);

		// Ignore directories that are not needed
        foreach ($this->foldersToIgnore as $folderToIgnore) {
            unset($files[array_search($folderToIgnore, $files, true)]);
        }

		// Loop through files and add to array. If directory, recursively call again.
        foreach($files as $key => $value){
            $path = $folder . DIRECTORY_SEPARATOR . $value;
            if (!is_dir($path)) {
                $results[] = $path;
            } else {
                $this->getAllFiles($path, $results);
            }
        }

        return $results;
    }
}