php - What does this get_text function do? -

panique did great job answering question on thread: php directory list remote server

but created function don't understand @ , hoping sort of explanation. example, what's random 8192 number?

function get_text($filename) {      $fp_load = fopen("$filename", "rb");      if ( $fp_load ) {              while ( !feof($fp_load) ) {                 $content .= fgets($fp_load, 8192);             }              fclose($fp_load);              return $content;      } } 

it loads file path in $filename , returns it's content. 8192 not random. means read file in chunks of 8kb.

the while loop runs long file wasn't entirely read. each iteration adds latest 8kb of file $content returned @ end of function.