ion.

     -s, --special-files
             Normally, file only attempts to read and determine the type of
             argument files which stat(2) reports are ordinary files.  This
             prevents problems, because reading special files may have pecu‐
             liar consequences.  Specifying the -s option causes file to also
             read argument files which are block or character special files.
             This is useful for determining the filesystem types of the data
             in ra