const units = ['bytes', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];
function niceBytes(x){
let l = 0, n = parseInt(x, 10) || 0;
while(n >= 1024 && ++l){
n = n/1024;
}
//include a decimal point and a tenths-place digit if presenting
//less than ten of KB or greater units
return(n.toFixed(n < 10 && l > 0 ? 1 : 0) + ' ' + units[l]);
}