file(1)file(1)NAMEfile - determine file type
SYNOPSIS
mfile] ffile] file ...
UNIX 2003 (onwards) Synopsis
mfile] Mfile] ffile] file ...
DESCRIPTION
performs a series of tests on each file in an attempt to classify it.
If file appears to be an ASCII file, examines the first 512 bytes and
tries to guess its language. If file is an executable file, prints the
version stamp, provided it is greater than 0 (see the description of
the option in ld(1)).
uses the file to identify files that have some sort of that is, any
file containing a numeric or string constant that indicates its type.
Commentary at the beginning of explains the format.
Options
recognizes the following command-line options:
Use alternate magic file
mfile.
(UNIX 2003 onwards Only)
Use alternate magic file Mfile. Do not apply default
context-sensitive tests.
Check the magic file for format errors.
This validation is not normally carried out for rea‐
sons of efficiency. No file classification is done
when this option is specified.
(UNIX 2003 onwards Only)
Apply position-sensitive tests from the default magic
file, and default context-sensitive tests to the
file.
Obtain the list of files to be examined from file
ffile. classifies each file whose name appears in
ffile.
Do not follow symbolic links.
From UNIX 2003 (onwards) environment, if is not spec‐
ified and the is a symbolic link referring to a non-
existent file, it is identified as a symbolic link,
as if has been specified.
Do not attempt to classify a regular file further.
If the option is specified with the option, 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
determines the language in which messages are displayed.
If is not specified in the environment or is set to the empty string,
the value of is used as a default for each unspecified or empty vari‐
able. If is not specified or is set to the empty string, a default of
"C" (see lang(5)) is used instead of
If any internationalization variable contains an invalid setting,
behaves as if all internationalization 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 command for a release interprets the core files for that particular
release correctly. Using the command on a core file generated on a
different release will report incorrect results.
SEE ALSOld(1), standards(5).
STANDARDS CONFORMANCEfile(1)
