|
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(4), attributes(5)
BUGS
file often makes mistakes. In particular, it often suggests that command files are C programs.
file does not recognize Pascal or LISP.