ตรวจสอบนามสกุลไฟล์ที่จะดาวโหลด แล้วโชว์ไอคอนตามนามสกุลนั้นๆอ่ะครับอ่ะครับ

$file_parts = pathinfo("www.abc.com/doc.pdf");

if($file_parts['extension'] == "pdf"){
       echo "pdf.png";
}else{
      something
}

$fileext = pathinfo('file.txt', PATHINFO_EXTENSION);

switch case ($fileext) {
    case 'txt':
        $image = 'txt.png';
        break;
    default:
        $image = 'unknown.png';
}

echo '<img src="' . $image . '" alt="' . $fileext . '">';

list($txt,$ext) = explode(".",$filename);
switch($ext){
    case "doc" : $img="doc.png";break;
    case "docx" : $img="docx.png";break;
    case "xls"  : $img="xls.png";break;
    case "xlsx"  : $img="xlsx.png";break;
    case "pdf" : $img="pdf.png";break;
    case "jpg" : $img="jpg.png";break;
    case "jpeg" : $img="jpeg.png";break;
    case "png" : $img="png.png";break;
    case "gif" : $img="gif.png";break;
    case "bmp" : $img="bmp.png";break;
    case "ppt" : $img="ppt.png";break;
    case "pptx" : $img="pptx.png";break;
    default:$img="eml.png";   
}