var dir = "/number";
var fileextension = ".pl";
$.ajax({
    url: dir,
    success: function (data) {


        $(data).find("a:contains(" + fileextension + ")").each(function () {
            var filename = this.href.replace([removed].host, "").replace("http:///", "");
            $("body").append($(dir + filename));
        });
    }

예제보면서하는데 .append()에 대해 설명만해놓고 호출하는법은 안알려줌 ㅠㅠ;;