Mac OS X Tiger in a Nutshell

Name

file

Synopsis

file [options] files

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

Options

-b, --brief

Brief mode: don’t print filenames.

-c, --checking-printout

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

-F separator, --separator separator

Print separator between file and type, instead of a colon.

-f file, --files-from file

Read the names of files to be checked from file.

-i, --mime

Print the MIME type of the file instead of a human-readable description.

-k, --keep-going

Don’t stop after the first match.

-L, --dereference

Follow symbolic links. By default, symbolic links are not followed.

-m file, --magic-file file

Search for file types in file instead of /etc/magic.

-N, --no-pad

Don’t pad filenames for alignment.

-v, --version

Print the version.

-z, --uncompress

Attempt checking of compressed files.

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

Apple QuickTime movie file (moov)
ASCII text
data
directory
gzip compressed data
empty
PDF document, version 1.4
Mach-O executable ppc
sticky symbolic link to private/tmp

Example

List all PDF Version 1.1 files:

$ file * | grep "PDF document, version 1.1"