disk_free_space

Transformation is possible WITHOUT using loops:<?php     $bytes = disk_free_space(".");     $si_prefix = array( 'B', 'KB', 'MB', 'GB', 'TB', 'EB', 'ZB', 'YB' );    $base = 1024;    $class = min((int)log($bytes , $base) , count($si_prefix) - 1);    echo $bytes . '<br />';    echo sprintf('%1.2f' , $bytes / pow($base,$class)) . ' ' . $si_prefix[$class] . '<br />';?>

$si_prefix = array( 'B', 'KB', 'MB', 'GB', 'TB', 'EB', 'ZB', 'YB' );you are missing the petabyte after terabyte 'B', 'KB', 'MB', 'GB', 'TB', 'EB', 'ZB', 'YB' should look like 'B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'

Nice, but please be aware of the prefixes.SI specifies a lower case 'k' as 1'000 prefix.It doesn't make sense to use an upper case 'K' as binary prefix,while the decimal Mega (M and following) prefixes in SI are uppercase.Furthermore, there are REAL binary prefixes since a few years.Do it the (newest and recommended) "IEC" way:KB's are calculated decimal; power of 10 (1000 bytes each)KiB's are calculated binary; power of 2 (1024 bytes each).The same goes for MB, MiB and so on...Feel free to read:http://en.wikipedia.org/wiki/Binary_prefix

Another easy way to convert bytes to human readable sizes would be this:<?phpfunction HumanSize($Bytes){  $Type=array("", "kilo", "mega", "giga", "tera", "peta", "exa", "zetta", "yotta");  $Index=0;  while($Bytes>=1024)  {    $Bytes/=1024;    $Index++;  }  return("".$Bytes." ".$Type[$Index]."bytes");}?>It simply takes the $Bytes and divides it by 1024 bytes untill it's no longer over or equal to 1024, meanwhile it increases the $Index to allocate which suffix belongs to the return (adding 'bytes' to the end to save some space).You can easily modify it so it's shorter, but I made it so it's more clearer.Nitrogen.

Note that disk_free_space() does an open_basedir check.

I have no idea why this function would return the number of bytes as a float, instead of an integer.  Is it possible to have 1.2 bytes for instance?