Displays the classification of a file
file [option] file-list
The file utility classifies files according to their contents.
The file-list contains the pathnames of one or more files that file classifies. You can specify any kind of file, including ordinary, directory, and special files, in the file-list.
file Takes the names of files to be examined from file rather than from the command line. The names of the files must be listed one per line in file.
zip Attempts to classify files within a compressed file.
The file utility can classify more than 5000 file types. Some of the more common file types found on GNU/Linux systems, as displayed by file, are
archive ascii text c program text commands text ...