Stop out put

programming
1

i have this code that works great

It does everything i want but a by product is its outputs all the time

is there anything to stop it outputing? If not then no worrys


if (!function_exists('mime_content_type')){
 $filetype = system(trim('file -bi ' . escapeshellarg ($filename)));
}else{
 $filetype = mime_content_type($file);
}

Cheers in advance