I will pipe compressed archives to the standard input of a bash script.
How can I determine in the same script the name (or rather the extension) of the file that has been piped to the script?

My aim is as follows:
1. Pipe compressed files to the script
2. Which should call the appropriate de-compression utility to list the contents (filenames) in the archive
3. It should then return a specific exit code if the archive contained a windows executable

standard input does not have a filename (unless you pass it as a parameter to the script)

you can try to guess the file type by using the "file" utility (which uses /etc/magic to determine the file type from the file header)

Well, my script will be specified an external scanner module called by a mail sanitizer in the case of compressed mail attachments.

So far I thought that the mail sanitizer passes the attachments to the standard input of such external scanner modules.

Now I rather think it saves the attachments to a temporary location and only passes the filename to the external modules.

If it is so, it is better, since I can then obtain the filename in $1, besides, e.g. unzip did not seem very eager to accept data to be uncompressed on its standard input...