Added req.get(field, param)

lib/request.js

@@ -65,6 +65,28 @@ req.header = function(name, defaultValue){
   }
 };
 
+/**
+ * Get `field`'s `param` value, defaulting to ''.
+ *
+ * Examples:
+ *
+ *    req.get('content-disposition', 'filename');
+ *    // => "something.png"
+ *
+ * @param {String} field
+ * @param {String} param
+ * @return {String}
+ * @api public
+ */
+
+req.get = function(field, param){
+  var val = this.header(field);
+  if (!val) return '';
+  var regexp = new RegExp(key + ' *= *(?:"([^"]+)"|([^;]+))', 'i');
+  if (!regexp.exec(val)) return '';
+  return RegExp.$1 || RegExp.$2;
+};
+
 /**
  * Check if the _Accept_ header is present, and includes the given `type`.
  *

test/request.test.js

@@ -303,5 +303,36 @@ module.exports = {
     assert.response(app,
       { url: '/incorrect', headers: { Referer: 'expressjs.com' }},
       { body: 'expressjs.com' });
+  },
+
+  'test #get(field, param)': function(){
+    var app = express.createServer();
+
+    app.get('/', function(req, res, next){
+      req.get('content-disposition', 'filename')
+        .should.equal('foo bar.jpg');
+
+      req.get('Content-Disposition', 'filename')
+        .should.equal('foo bar.jpg');
+
+      req.get('x-content-foo', 'foo').should.equal('bar');
+      req.get('x-content-foo', 'bar').should.equal('foo bar baz');
+      req.get('x-content-foo', 'woot').should.equal('tobi loki jane');
+      req.get('cache-control', 'max-age').should.equal('500');
+
+      req.get('foo').should.equal('');
+      req.get('foo', 'bar').should.equal('');
+      res.end();
+    });
+
+    var fields = {
+        'Content-Disposition': 'attachment; filename="foo bar.jpg"'
+      , 'X-Content-Foo': 'foo=bar; bar=foo bar baz; woot=tobi loki jane;'
+      , 'Cache-Control': 'max-age =   500'
+    };
+
+    assert.response(app,
+      { url: '/', headers: fields },
+      { body: '' });
   }
 };