var app = angular.module('plunker', []);

app.controller('MainCtrl', function($scope) {
  $scope.name = 'World';
})
.directive('linkFunctionTest', function(){
  
  return {
    template: '<p>This is my directive content</p>',
    link: function(scope, el, attrs) {
      el.find('p').css('color', 'red');
          }
  }
});
<!DOCTYPE html>
<html ng-app="plunker">

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="style.css" />
    <script data-require="angular.js@1.4.x" src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.4.6/angular.min.js" data-semver="1.4.6"></script>
    <script src="app.js"></script>
  </head>

  <body ng-controller="MainCtrl">
    <p>Hello {{name}}!</p>
    <link-function-test></link-function-test>
  </body>
  

</html>
/* Put your css in here */