How to detect the server space enough for the uploaded file or no?

开发者_Go百科I am have uploading site and I want to know how i can know the space of the server via php ?

for example:

if($_FILES ...) {
  if($server_rest_space enough for the file){
    // upload it!
}
else{
  echo 'no space on your server enough!'; //there is no space!!
}

important another question if the server is full! and some one uploaded file is there an error will happen ?

thank you

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Try to use disk_free_space()