Is it possible to execute an external program?

[PetersOtto]

Hello!
I'm playing around with ImageMagic and Yellow. I'm trying to use filters and use, as starting point the following function as a test inside the image.php:

    public function nashville($image)
    {
        $image = $this->execute("convert $image -contrast -modulate 100,150,100 -auto-gamma $image");
        return $image;
    }

Unfortunately I get an error message.

PHP Fatal error: Uncaught Error: Call to undefined method YellowImage::execute() in /var/www/html/test/system/extensions/image.php:265\nStack trace:\n#0 ...

Could it be that execute() is not allowed in Yellow? Perhaps for safety reasons? If it is allowed, maybe someone has a tip on how I can proceed? 😟

[schulle4u]

Yellow doesn't block any PHP functions. Whatever your web host allows, it is also allowed in Yellow extensions. The error message states that you are trying to call an undefined method in your code. Maybe try exec instead?

[PetersOtto]

Hi Steffen,
thank you very much for your answer. Then I can rule out Yellow as a source of error.
I think I'll have to get to grips with ImageMagick a bit more first.
Have a nice weekend!

[GiovanniSalmeri]

Please remark that:

1. exec and similar functions can be disabled in a specific installation of PHP for security reasons;
2. Imagick may be installed as an extension of PHP: in this case it is much better to use the corresponding functions of PHP rather than execute Imagick as an external program.

[PetersOtto]

Hello Giovanni.
Thanks for the tip!