file

file [options] files

Classify the named files according to the type of data they contain. file checks the magic file (usually /etc/magic) to identify many common file types.

Options

-c

Check the format of the magic file (files argument is invalid with -c).

-flist

Run file on the filenames in list.

-h

Do not follow symbolic links.

-mfile

Use file as the magic file instead of /etc/magic.

Many file types are understood. Output lists each filename, followed by a brief classification such as:

ascii text
c program text
c-shell commands
data
empty
iAPX 386 executable
directory
[nt]roff, tbl, or eqn input text
shell commands
symbolic link to ../usr/etc/arp

Example

List all files that are deemed to be nroff/troff input:

file * | grep roff