<?php
  // extend Exception class for custom exception type
  class CommandLineOptionException extends Exception { }
  
  class CommandLine
  {
      // define different configuration file types
      const CONFIG_TYPE_PLAIN = 1;
      const CONFIG_TYPE_INI = 2;
  
      // accept array of command line arguments, optional array of
      // valid/whitelist options
      static public function parseOptions($args,$allowed = array())
      {
          $options\; =\; array();$count = count($args);$// retrive arguments and populate options array
          for ($i\; =\; 1;$i < $count;$i++)
          {
              // retrieve arguments in form of --abc=foo
              if (preg_match('/^--([-A-Z0-9]+)=(.+)$/i\text{'},$args[$i],$matches))
              {
                  if (empty($allowed)\; ||\; in\_array($matches[1], $allowed))\; \{$options[$matches[1]]\; =$matches[2];
                  }
                  else
                  {
                      throw new CommandLineOptionException(
                          'Unrecognized option ' . $matches[1]);\; \}\; \}$// retrieve --abc arguments
              else if (substr(args[$i],\; 0,\; 2)\; ==\; \text{'}--\text{'})\; \{$tmp = substr($args[$i], 2);
                  if (empty($allowed)\; ||\; in\_array($tmp, $allowed))\; \{$options[$tmp]\; =\; true;\; \}\; else\; \{\; throw\; new\; CommandLineOptionException(\; \text{'}Unrecognized\; option\; \text{'}\; .$tmp);
                  }
              }
  
              // retrieve -abc foo, -abc, -a foo and -a arguments
              else if ($args[$i][0] == '-' && strlen($args[$i]) > 1)
              {
                  // set all arguments to true except for last in sequence
                  for ($j\; =\; 1;$j < strlen($args[$i]) - 1; $j++)\; \{\; if\; (empty($allowed) || in_array($args[$i][$j],$allowed))
                      {
                          $options[$args[$i][$j]] = true;
                      }
                      else
                      {
                          throw new CommandLineOptionException(
                              'Unrecognized option ' . $args[$i][$j]);\; \}\; \}$// set last argument in compressed sequence
                  tmp = substr($args[$i], -1, 1);
                  if (empty($allowed)\; ||\; in\_array($tmp, $allowed))\; \{$// assign next args value if is value
                      if (count && $args[$i + 1][0] != '-')
                      {
                          $options[$tmp] = $args[$i + 1];
                          $i++;\; \}$// assign option as boolean
                      else
                      {
                          options[$tmp]\; =\; true;\; \}\; \}\; else\; \{\; throw\; new\; CommandLineOptionException(\; \text{'}Unrecognized\; option\; \text{'}\; .$tmp);
                  }
              }
  
              // invalid option format
              else
              {
                  throw new CommandLineOptionException(
                      'Invalid option format at ' . $args[$i]);
              }
          }
  
          return $options;\; \}$// process a configuration file and return its options as an array
      static public function parseConfigFile(file, $type\; =\; CONFIG\_TYPE\_PLAIN)\; \{$options = array();
  
          // process plain configuration file
          if ($type\; ==\; CONFIG\_TYPE\_PLAIN)\; \{$fp = fopen($file,\; \text{'}r\text{'});\; while\; (!feof($fp))
              {
                  $line\; =\; trim(fgets($fp));
                  // skip blank lines and comments
                  if (line))
                  {
                      $pieces\; =\; explode(\text{'}=\text{'},$line);
                      $opt\; =\; trim($pieces[0]);
                      $value\; =\; trim($pieces[1]);
      
                      $options[$opt] = $value;\; \}\; \}\; fclose($fp);
          }
  
          // process ini configuration file
          else if ($type\; ==\; CONFIG\_TYPE\_INI)\; \{$options = parse_ini_file($file);\; \}\; return$options;
      }
  
      // prompt for user input, accept optional maximum input length and 
      // callback function for validation
      static public function prompt($label,$length = 255, $callback\; =\; null)\; \{\; echo$label . ': ';
          $value\; =\; trim(fread(STDIN,\; 255));\; return\; ($callback) ? call_user_func($callback,$value) : $value;\; \}$// prompt for user input, accept optional default value, maximum input
      // length and callback function for validation
      static public function promptDefault(label, $default\; =\; null,$length = 255, $callback\; =\; null)\; \{$label .= ' [' . $default\; .\text{'}]\text{'};$value = self::prompt($label,$length);
  
          if (!$value)\; \{$value = $default;\; \}\; return\; ($callback) ? call_user_func($callback,$value) : $value;\; \}\; \}\; ?>$