format bytes to the best fitted unit

formatbytes.php

#!/usr/bin/env php
<?php
 
function formatBytes($bytes, $precision = 2) {
    $units = array('B', 'KB', 'MB', 'GB', 'TB');
    $bytes = max($bytes, 0);
    $pow = floor(($bytes ? log($bytes) : 0) / log(1024));
    $pow = min($pow, count($units) - 1);
    $bytes /= (1 << (10 * $pow));
           
    return sprintf('%4.02f %s', round($bytes, $precision), $units[$pow]);
}

if (2 !== $argc) {
    printf("Usage: %s [bytes]\n", $argv[0]);
        
    exit(-1);
}

list(, $bytes) = $argv;

printf("%s => %s\n", $bytes, formatBytes($bytes));