File-Magic is a versatile file management tool that simplifies the task of opening, and handling a large range of file formats, especially complex and multifaceted "dot" file types.
In case you encounter frequently-used file extensions including .pdf, and even more obscure ones like . https://www.filemagic.com/en/page-layout-files/dot-file-extension/1-solution-for-all-your-dot-file-issues/