bash, getting the mime type of a file handle

Question

How would i get the mime type of a file-handle without saving it to disk?

What i mean is a file that is not saved to disk, rather: i extracted it from an archive and plan on piping it to another script.

Say i extracted the file like this:

tar -xOzf images.tar.gz images/logo.jpg | myscript

Now inside myscript I would like to check the mime type of the file before further processing it. How would it go about this?

Answer 1

as some people think my comment above is helpful i post it as an answer. the file-command is able to determine a file's mime type on the fly/when being piped. It ist able to read a file from stdin - printing the file's --mime-type briefly/in a short manner when passing -b. Considering your example you probably want to extract a single file from an archive and dertermine its file/mime type.

$ tar -xOzf foo.tar.gz file_in_archive.txt | file -b --mime-type -
text/plain

so for a simple text file extracted from an archive to stdout it could look like the example above. hope that helped. regards