php实现压缩合并js的方法【附demo源码下载】

require_once('jsmin.php');
$files = glob("js/*.js");
$js = "";
foreach($files as $file) {
  $js .= jsmin::minify(file_get_contents($file));
}
file_put_contents("combined.js", $js);
echo "success";

<?php
/**
 * jsmin.php - php implementation of douglas crockford's jsmin.
 *
 * this is pretty much a direct port of jsmin.c to php with just a few
 * php-specific performance tweaks. also, whereas jsmin.c reads from stdin and
 * outputs to stdout, this library accepts a string as input and returns another
 * string as output.
 *
 * php 5 or higher is required.
 *
 * permission is hereby granted to use this version of the library under the
 * same terms as jsmin.c, which has the following license:
 *
 * --
 * copyright (c) 2002 douglas crockford (www.crockford.com)
 *
 * permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "software"), to deal in
 * the software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the software, and to permit persons to whom the software is furnished to do
 * so, subject to the following conditions:
 *
 * the above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the software.
 *
 * the software shall be used for good, not evil.
 *
 * the software is provided "as is", without warranty of any kind, express or
 * implied, including but not limited to the warranties of merchantability,
 * fitness for a particular purpose and noninfringement. in no event shall the
 * authors or copyright holders be liable for any claim, damages or other
 * liability, whether in an action of contract, tort or otherwise, arising from,
 * out of or in connection with the software or the use or other dealings in the
 * software.
 * --
 *
 * @package jsmin
 * @author ryan grove <ryan@wonko.com>
 * @copyright 2002 douglas crockford <douglas@crockford.com> (jsmin.c)
 * @copyright 2008 ryan grove <ryan@wonko.com> (php port)
 * @copyright 2012 adam goforth <aag@adamgoforth.com> (updates)
 * @license http://opensource.org/licenses/mit-license.php mit license
 * @version 1.1.2 (2012-05-01)
 * @link https://github.com/rgrove/jsmin-php
 */
class jsmin {
 const ord_lf      = 10;
 const ord_space     = 32;
 const action_keep_a   = 1;
 const action_delete_a  = 2;
 const action_delete_a_b = 3;
 protected $a      = '';
 protected $b      = '';
 protected $input    = '';
 protected $inputindex = 0;
 protected $inputlength = 0;
 protected $lookahead  = null;
 protected $output   = '';
 // -- public static methods --------------------------------------------------
 /**
  * minify javascript
  *
  * @uses __construct()
  * @uses min()
  * @param string $js javascript to be minified
  * @return string
  */
 public static function minify($js) {
  $jsmin = new jsmin($js);
  return $jsmin->min();
 }
 // -- public instance methods ------------------------------------------------
 /**
  * constructor
  *
  * @param string $input javascript to be minified
  */
 public function __construct($input) {
  $this->input    = str_replace("\r\n", "\n", $input);
  $this->inputlength = strlen($this->input);
 }
 // -- protected instance methods ---------------------------------------------
 /**
  * action -- do something! what to do is determined by the $command argument.
  *
  * action treats a string as a single character. wow!
  * action recognizes a regular expression if it is preceded by ( or , or =.
  *
  * @uses next()
  * @uses get()
  * @throws jsminexception if parser errors are found:
  *     - unterminated string literal
  *     - unterminated regular expression set in regex literal
  *     - unterminated regular expression literal
  * @param int $command one of class constants:
  *   action_keep_a   output a. copy b to a. get the next b.
  *   action_delete_a  copy b to a. get the next b. (delete a).
  *   action_delete_a_b get the next b. (delete b).
 */
 protected function action($command) {
  switch($command) {
   case self::action_keep_a:
    $this->output .= $this->a;
   case self::action_delete_a:
    $this->a = $this->b;
    if ($this->a === "'" || $this->a === '"') {
     for (;;) {
      $this->output .= $this->a;
      $this->a    = $this->get();
      if ($this->a === $this->b) {
       break;
      }
      if (ord($this->a) <= self::ord_lf) {
       throw new jsminexception('unterminated string literal.');
      }
      if ($this->a === '\\') {
       $this->output .= $this->a;
       $this->a    = $this->get();
      }
     }
    }
   case self::action_delete_a_b:
    $this->b = $this->next();
    if ($this->b === '/' && (
      $this->a === '(' || $this->a === ',' || $this->a === '=' ||
      $this->a === ':' || $this->a === '[' || $this->a === '!' ||
      $this->a === '&' || $this->a === '|' || $this->a === '?' ||
      $this->a === '{' || $this->a === '}' || $this->a === ';' ||
      $this->a === "\n" )) {
     $this->output .= $this->a . $this->b;
     for (;;) {
      $this->a = $this->get();
      if ($this->a === '[') {
       /*
        inside a regex [...] set, which may contain a '/' itself. example: mootools form.validator near line 460:
         return form.validator.getvalidator('isempty').test(element) || (/^(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]\.?){0,63}[a-z0-9!#$%&'*+/=?^_`{|}~-]@(?:(?:[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\.)*[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\])$/i).test(element.get('value'));
       */
       for (;;) {
        $this->output .= $this->a;
        $this->a = $this->get();
        if ($this->a === ']') {
          break;
        } elseif ($this->a === '\\') {
         $this->output .= $this->a;
         $this->a    = $this->get();
        } elseif (ord($this->a) <= self::ord_lf) {
         throw new jsminexception('unterminated regular expression set in regex literal.');
        }
       }
      } elseif ($this->a === '/') {
       break;
      } elseif ($this->a === '\\') {
       $this->output .= $this->a;
       $this->a    = $this->get();
      } elseif (ord($this->a) <= self::ord_lf) {
       throw new jsminexception('unterminated regular expression literal.');
      }
      $this->output .= $this->a;
     }
     $this->b = $this->next();
    }
  }
 }
 /**
  * get next char. convert ctrl char to space.
  *
  * @return string|null
  */
 protected function get() {
  $c = $this->lookahead;
  $this->lookahead = null;
  if ($c === null) {
   if ($this->inputindex < $this->inputlength) {
    $c = substr($this->input, $this->inputindex, 1);
    $this->inputindex += 1;
   } else {
    $c = null;
   }
  }
  if ($c === "\r") {
   return "\n";
  }
  if ($c === null || $c === "\n" || ord($c) >= self::ord_space) {
   return $c;
  }
  return ' ';
 }
 /**
  * is $c a letter, digit, underscore, dollar sign, or non-ascii character.
  *
  * @return bool
  */
 protected function isalphanum($c) {
  return ord($c) > 126 || $c === '\\' || preg_match('/^[\w\$]$/', $c) === 1;
 }
 /**
  * perform minification, return result
  *
  * @uses action()
  * @uses isalphanum()
  * @uses get()
  * @uses peek()
  * @return string
  */
 protected function min() {
  if (0 == strncmp($this->peek(), "\xef", 1)) {
    $this->get();
    $this->get();
    $this->get();
  } 
  $this->a = "\n";
  $this->action(self::action_delete_a_b);
  while ($this->a !== null) {
   switch ($this->a) {
    case ' ':
     if ($this->isalphanum($this->b)) {
      $this->action(self::action_keep_a);
     } else {
      $this->action(self::action_delete_a);
     }
     break;
    case "\n":
     switch ($this->b) {
      case '{':
      case '[':
      case '(':
      case '+':
      case '-':
      case '!':
      case '~':
       $this->action(self::action_keep_a);
       break;
      case ' ':
       $this->action(self::action_delete_a_b);
       break;
      default:
       if ($this->isalphanum($this->b)) {
        $this->action(self::action_keep_a);
       }
       else {
        $this->action(self::action_delete_a);
       }
     }
     break;
    default:
     switch ($this->b) {
      case ' ':
       if ($this->isalphanum($this->a)) {
        $this->action(self::action_keep_a);
        break;
       }
       $this->action(self::action_delete_a_b);
       break;
      case "\n":
       switch ($this->a) {
        case '}':
        case ']':
        case ')':
        case '+':
        case '-':
        case '"':
        case "'":
         $this->action(self::action_keep_a);
         break;
        default:
         if ($this->isalphanum($this->a)) {
          $this->action(self::action_keep_a);
         }
         else {
          $this->action(self::action_delete_a_b);
         }
       }
       break;
      default:
       $this->action(self::action_keep_a);
       break;
     }
   }
  }
  return $this->output;
 }
 /**
  * get the next character, skipping over comments. peek() is used to see
  * if a '/' is followed by a '/' or '*'.
  *
  * @uses get()
  * @uses peek()
  * @throws jsminexception on unterminated comment.
  * @return string
  */
 protected function next() {
  $c = $this->get();
  if ($c === '/') {
   switch($this->peek()) {
    case '/':
     for (;;) {
      $c = $this->get();
      if (ord($c) <= self::ord_lf) {
       return $c;
      }
     }
    case '*':
     $this->get();
     for (;;) {
      switch($this->get()) {
       case '*':
        if ($this->peek() === '/') {
         $this->get();
         return ' ';
        }
        break;
       case null:
        throw new jsminexception('unterminated comment.');
      }
     }
    default:
     return $c;
   }
  }
  return $c;
 }
 /**
  * get next char. if is ctrl character, translate to a space or newline.
  *
  * @uses get()
  * @return string|null
  */
 protected function peek() {
  $this->lookahead = $this->get();
  return $this->lookahead;
 }
}
// -- exceptions ---------------------------------------------------------------
class jsminexception extends exception {}
?>