text: // gulp mcss plugin
  var through = require('through2');
  var gutil = require('gulp-util');
  var path = require('path');
  var fs = require('fs');
  
  var PluginError = gutil.PluginError;
  
  var extend = function(o1, o2, override){
    for(var i in o2) if(override || o1[i] === undefined){
      o1[i] = o2[i]
    }
    return o1;
  }
  
  module.exports = function (opt) {
  
    function transform(file, enc, cb) {
      if (file.isNull()) return cb(null, file); 
      if (file.isStream()) return cb(new PluginError('gulp-mcss', 'Streaming not supported'));
  
      var str = file.contents.toString('utf8');
  
      var str_zh = str.replace(/<\!-- t -->[\s\S]*?<\!-- s -->/g, "").replace(/\{([^{}]+)\%([^{}]+)\}/g,function(all, one, two){
        return two;
      })
      var str_en = str.replace(/<\!-- s -->[\s\S]*?<\!-- \/t -->/g, "").replace(/\{([^\{}]+)\%([^\{}]+)\}/g,function(all, one, two){
        return one;
      })
  
  
  
      var file_zh = new gutil.File({
        cwd: "",
        base: "",
        path: path.basename(file.path).replace(".md", "-zh.md"),
        contents: new Buffer(str_zh)
      });
      var file_en = new gutil.File({
        cwd: "",
        base: "",
        path: path.basename(file.path).replace(".md", "-en.md"),
        contents: new Buffer(str_en)
      });
  
      this.push(file_zh);
      this.push(file_en);
      cb(null);
    }
  
    return through.obj(transform);
  };