如何检查上传的文件是pdf ..还是图像？

Question

 <p class="card-text">
                          
                           <?php echo htmlentities($result2->PostBody);?>
                        </p>
                        <?php 
                        if($result2->URL)
                            { 
                               
                                ?>
                                    <a href=""><?php echo htmlentities($result2->URL);?></a>
                                
                      <?php    } ?>
                    </div>

 if(isset($_POST['share'])){
                        $gid=intval(openssl_decrypt($_GET['gid'],"AES-128-ECB", SECRETKEY));
                        $sid=$_SESSION['login'];
                        /*$vimage1=$_FILES["profile"]["name"];
                        move_uploaded_file($_FILES["profile"]["tmp_name"],"img/".$_FILES["profile"]["name"]);*/
                        $allowedExts = array("doc", "docx", "pdf", "gif", "jpeg", "jpg", "png", "pptx" ,"ppt","xlsx","xls");
                        if (($_FILES["file"]["type"] == "application/pdf") || ($_FILES["file"]["type"] == "application/msword") ||  ($_FILES["file"]["type"] == "application/vnd.ms-excel") ||($_FILES["file"]["type"] == "application/vnd.ms-powerpoint") || ($_FILES["file"]["type"]="application/vnd.openxmlformats-officedocument.wordprocessingml.document") ||($_FILES["file"]["type"] == "application/vnd.openxmlformats-officedocument.presentationml.presentation") || ($_FILES["file"]["type"] == "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet") || ($_FILES["file"]["type"] == "image/gif") || ($_FILES["file"]["type"] == "image/jpeg") || ($_FILES["file"]["type"] == "image/jpg")  || ($_FILES["file"]["type"] == "image/png") && ($_FILES["file"]["size"] < 20000000) && in_array(end(explode(".", $_FILES["file"]["name"])), $allowedExts))
                        {
                             $sql="insert into Posts (PostBody,URL, PostStatus, 
                                    PID, GroupID) values(:cbody,:vimage1, 1, :userid, :group)";
                        }
                        $query = $dbh->prepare($sql);
                        $query -> bindParam(':cbody',$_POST['post'], PDO::PARAM_STR);
                        $query->bindParam(':vimage1',$_FILES["file"]["name"],PDO::PARAM_STR);
                        $query-> bindParam(':userid',$sid, PDO::PARAM_INT);
                        $query-> bindParam(':group',$gid, PDO::PARAM_INT);
                        $query -> execute();
                        //$query->debugDumpParams();			
	               }

我成功地将帖子和文件插入数据库，但是我的问题是如何检查上传的文件的类型以显示它，例如，如果我上传pdf文件，我需要在href标记中显示它，而如果我上传图像我需要在图片标签中显示