file(1) file(1)
NAME
file - determine file type
SYNOPSIS
file [-c] [-f ffile] [-m mfile] arg ...
DESCRIPTION
file performs a series of tests on each file named in its
arguemnts in an attempt to classify it. If file appears to
be ASCII, file examines the first 512 bytes and tries to
guess its language. If a file is an executable a.out file,
file will print the version stamp, provided it is greater
than 0 (see ld(1)).
If the -f flag option is given, the next argument is taken
to be a file containing the names of the files to be
examined.
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 its
format.
The -m flag option instructs file to use an alternate magic
file.
The -c flag option causes file to check the magic file for
format errors. This validation is not normally carried out
for reasons of efficiency. No file typing is done under -c.
EXAMPLE
file textfile programfile directory
reports the file names and directory name, and whether the
files are English text, nroff input, a C program, or
whatever.
FILES
/bin/file
SEE ALSO
ld(1).
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