FILE(1B) BSD Compatibility Package Commands FILE(1B)

NAME

file - determine the type of a file by examining its contents

SYNOPSIS

/usr/ucb/file [-f ffile] [-cL] [-m mfile] filename...

DESCRIPTION

file performs a series of tests on each filename in an attempt to
determine what it contains. If the contents of a file appear to be
ASCII text, file examines the first 512 bytes and tries to guess its
language.


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.

OPTIONS

-c
Check for format errors in the magic number file. For
reasons of efficiency, this validation is not normally
carried out. No file type-checking is done under -c.


-f ffile
Get a list of filenames to identify from ffile.


-L
If a file is a symbolic link, test the file the link
references rather than the link itself.


-m mfile
Use mfile as the name of an alternate magic number file.

EXAMPLES

Example 1: Using file on all the files in a specific user's directory.

This example illustrates the use of file on all the files in a
specific user's directory:


example% pwd
/usr/blort/misc


example% /usr/ucb/file *

code: mc68020 demand paged executable
code.c: c program text
counts: ascii text
doc: roff,nroff, or eqn input text
empty.file: empty
libz: archive random library
memos: directory
project: symbolic link to /usr/project
script: executable shell script
titles: ascii text
s5.stuff: cpio archive


example%

ENVIRONMENT VARIABLES

The environment variables LC_CTYPE, LANG, and LC_default control the
character classification throughout file. On entry to file, these
environment variables are checked in the following order: LC_CTYPE,
LANG, and LC_default. When a valid value is found, remaining
environment variables for character classification are ignored. For
example, a new setting for LANG does not override the current valid
character classification rules of LC_CTYPE. When none of the values
is valid, the shell character classification defaults to the
POSIX.1 "C" locale.

FILES

/etc/magic

SEE ALSO

magic(5), attributes(7)

BUGS

file often makes mistakes. In particular, it often suggests that
command files are C programs.


file does not recognize Pascal or LISP.

September 14, 1992 FILE(1B)