Get the free space function for a Windows disk

<?PHP/** Get the remaining space on a disk * $param associative array, the subscript is which disk, unit, can be B,KB,MB,GB * can be set to get multiple disks, for example: Array (' C ' = = ' KB ', ' D ' = = ' mb ', ' E ' + ' GB ') ' F ' = ' B ') * If there is an error, return false*/    functionSpace ($arr){        //Check Parameters        if(Is_array($arr)){            //Initialize stored values            $memory=Array(); foreach($arr  as $disk=$size){                $D=Strtoupper($disk).‘:‘;//keyboard path converted to uppercase                $S=Strtoupper($size);//units converted to uppercase                if(In_array($D,Array(' C: ', ' D: ', ' E: ', ' F: ')) &&In_array($S,Array(' B ', ' KB ', ' MB ', ' GB ', ' TB ')))){                    Switch($S){                         Case' B ':$memory[$disk]=Disk_free_space($D).‘ B;  Break;  Case' KB ':$d=round(Disk_free_space($D)/1024); $memory[$disk] =$d.‘ KB ';  Break;  Case' MB ':$d=round(Disk_free_space($D) /POW(1024,2)); $memory[$disk]=$d.‘ MB ';  Break;  Case' GB ':$d=round(Disk_free_space($D) /POW(1024,3)); $memory[$disk]=$d.‘ GB ';  Break;  Case' TB ':$d=sprintf("%.4f",Disk_free_space($D) /POW(1024,4)); $memory[$disk] =$d.‘ TB ';  Break; default:return0;  Break; }                }Else{                    return NULL; }            }            return $memory; }Else{            return NULL; }    }    $arr=Array(' c ' = ' = ' kb ', ' d ' = ' Mb ', ' e ' = ' Gb ', ' f ' = ' Tb '); Var_dump(Space ($arr));

Get the free space function for a Windows disk