I am building a web application.
On one of the pages there is an upload form, where user can upload a file. After the upload is done, I want to check on the server if the uploaded file is an image.
Is it possible to check this beyond simple file extension checking (i.e. not assuming that a
*.png filename is actually a PNG image)?
For example, if I edit a JPEG image adding/editing a byte in a random place to make an invalid JPEG file, I want to detect that it is not a JPEG image anymore. I used to do such type of thing via PHP some time ago, using a GD library.
I would like to know if it is possible to do with Go?