jkuchar/BigFileTools

<?php

namespace BigFileTools\Driver;
use Brick\Math\BigInteger;
use Brick\Math\Exception\ArithmeticException;

class ExecDriver implements ISizeDriver
{
    private $os;
    const OS_WINDOWS = "Windows";
    const OS_LINUX = "Linux";
    const OS_MAC = "Mac";

    public function __construct()
    {
        if (!function_exists("exec")) {
            throw new PrerequisiteException("Exec function is disabled");
        }

        if(strtoupper(substr(PHP_OS, 0, 3)) == 'WIN') {
            $this->os = self::OS_WINDOWS;
        } elseif (strtoupper(PHP_OS) == "DARWIN") {
            $this->os = self::OS_MAC;
        } else {
            $this->os = self::OS_LINUX;
        }
    }

    /**
     * Returns file size by using system shell/cmd commands
     * @inheritdoc
     * @link http://stackoverflow.com/questions/5501451/php-x86-how-to-get-filesize-of-2gb-file-without-external-program/5502328#5502328
     * @return BigInteger
     */
    public function getFileSize($path)
    {
        switch($this->os) {
            case self::OS_WINDOWS: return $this->getFileSizeWindows($path); break;
            case self::OS_LINUX:   return $this->getFileSizeLinux($path); break;
            case self::OS_MAC:     return $this->getFileSizeMac($path); break;
            default: throw new Exception("OS not detected");
        }
    }

    /**
     * Convert string into integer
     * Must be precise number, otherwise you will see and exception.
     *
     * @param $valueAsString
     * @return BigInteger
     * @throws Exception
     */
    private function convertToInteger($valueAsString) {
        if(!is_string($valueAsString)) {
            throw new Exception("Cannot convert to integer. Expected string, but got " . gettype($valueAsString). ".");
        }
        $trimmedInput = trim($valueAsString);

        try {
            return BigInteger::of($trimmedInput);

        } catch (ArithmeticException $e) {
            throw new Exception("Returned value cannot be converted to an integer.",0, $e);
        }

    }

    private function getFileSizeWindows($path)
    {
        $escapedPath = escapeshellarg($path);
        return $this->convertToInteger(
            exec("for %F in ($escapedPath) do @echo %~zF")
        );
    }

    private function getFileSizeLinux($path)
    {
        $escapedPath = escapeshellarg($path);
        return $this->convertToInteger(
            exec("stat -Lc%s $escapedPath")
        );
    }

    private function getFileSizeMac($path)
    {
        $escapedPath = escapeshellarg($path);
        return $this->convertToInteger(
            exec("stat -f%z $escapedPath")
        );
    }
}