file.1 (2010 09)

f
file(1) file(1)
NAME
file - determine file type
SYNOPSIS
file [-m mfile ][
-c ][-f ffile ][-h ][-i ] file ...
UNIX 2003 (onwards) Synopsis
file [-m mfile ][
-M Mfile ][-c ][-d ][-f ffile ][
-h ][-i ] file ...
DESCRIPTION
file performs a series of tests on each file in an attempt to classify it. If file appears to be an ASCII file,
file examines the first 512 bytes and tries to guess its language. If file is an executable
a.out file,
file prints the version stamp, provided it is greater than 0 (see the description of the
-V option in
ld(1)).
file uses the file /etc/magic to identify files that have some sort of magic number, that is, any file
containing a numeric or string constant that indicates its type. Commentary at the beginning of
/etc/magic explains the format.
Options
file recognizes the following command-line options:
-m mfile Use alternate magic file mfile .
-M Mfile (UNIX 2003 onwards Only) Use alternate magic file Mfile . Do not apply default
context-sensitive tests.
-c Check the magic file for format errors. This validation is not normally carried out for
reasons of efficiency. No file classification is done when this option is specified.
-d (UNIX 2003 onwards Only) Apply position-sensitive tests from the default magic file,
/etc/magic, and default context-sensitive tests to the file.
-f ffile Obtain the list of files to be examined from file ffile .
file classifies each file whose
name appears in ffile .
-h Do not follow symbolic links. From UNIX 2003 (onwards) environment, if -h
is not
specified and the
file is a symbolic link referring to a non-existent file, it is identified
as a symbolic link, as if -h has been specified.
-i Do not attempt to classify a regular file further.
If the
-M option is specified with the -d option, -m option, or both, the concatenation of the
position-sensitive tests specified by these options is applied in the order specified by the appearance
of these options.
EXTERNAL INFLUENCES
For information about the UNIX standard environment, see standards (5).
Environment Variables
LC_MESSAGES determines the language in which messages are displayed.
If
LC_MESSAGES is not specified in the environment or is set to the empty string, the value of LANG is
used as a default for each unspecified or empty variable. If LANG is not specified or is set to the empty
string, a default of "C" (see lang (5)) is used instead of LANG.
If any internationalization variable contains an invalid setting,
file behaves as if all internationaliza-
tion variables are set to "C". See environ (5).
International Code Set Support
Single- and multi-byte character code sets are supported. However, all non-ASCII text files are identified
as "data".
WARNINGS
The
file command for a release interprets the core files for that particular release correctly. Using the
file command on a core file generated on a different release will report incorrect results.
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1