there is pdfinfo for PDFs, exifinfo for images, ffprobe for multimedia and so on. are the a collection or a standardized toolset for extracting filetype dependent(like pdf, image, doc, odt) metadata of all files in linux?
or even distinct tool that are file-format specific for most common file types like ppt, epub and other file types we commonly find in internet downloads.
Exiftool can extract metadata from more than just images. See Supported File Types.