I've heard from a few people that UNIX-like OSes don't have file extensions (example.jpg, etc). I've never used anything other than Windows, so this seems a little odd to me.

I assume the area of the file containing information about it, and which filetype it is, is called metadata (viewing the HTML of various pages reveals "meta" tags, detailing content/author, etc).. I also assume that the information detailing what type of file it is is called the "MIME type". Is this correct?

So... if I save a plain old text file in KWrite, and email it to a Windows user, will they see it as filename.txt, or just filename? Do I need to specify a .txt, .jpg, .c, etc extension for Windows users to see it?

Actually file extensions are there and not there.

It's funny really for people coming from a windows world.

Linux doesn't use the extension to determine the file-type. It uses the mime-type which is stored in each file.

Therefore executables don't need any extensions. As long as they're marked as executables, they'll work.

When saving files from programs in Linux, you NEED to specify the extension. Therefore I hope that answers your question.


EDIT: And oh, when using KWrite and you want to be able to use the file in Windows, then you need to set the End of Line to Windows/DOS from the "Tools" menu.