package format import "fmt" func FormatFileSize(bytes int64) string { const unit = 1024 if bytes < unit { return fmt.Sprintf("%d B", bytes) } div, exp := int64(unit), 0 for n := bytes / unit; n >= unit; n /= unit { div *= unit exp++ } return fmt.Sprintf("%.1f %cB", float64(bytes)/float64(div), "KMGTPE"[exp]) }