src/includes/classes/Core/Utils/FileSize.php
public function abbr(string $file): string
    {
        if (!$file) {
            return ''; // Empty.
        } elseif (!is_file($file)) {
            return ''; // Not possible.
        } elseif (!is_readable($file)) {
            return ''; // Not possible.
        }
        return $this->bytesAbbr(filesize($file));
    }
public function abbr(string $file): string
    {
        if (!$file) {
            return ''; // Empty.
        } elseif (!is_file($file)) {
            return ''; // Not possible.
        } elseif (!is_readable($file)) {
            return ''; // Not possible.
        }
        return $this->bytesAbbr(filesize($file));
    }
Abbreviated byte notation.

@since 150424 Initial release.

@param string $file Absolute file path.

@return string Abbreviated byte notation.