Sun Microsystems, Inc. gratefully acknowledges The Open Group for
permission to reproduce portions of its copyrighted documentation.
Original documentation from The Open Group can be obtained online at
http://www.opengroup.org/bookstore/.
The Institute of Electrical and Electronics Engineers and The Open
Group, have given us permission to reprint portions of their
documentation.
In the following statement, the phrase ``this text'' refers to portions
of the system documentation.
Portions of this text are reprinted and reproduced in electronic form
in the SunOS Reference Manual, from IEEE Std 1003.1, 2004 Edition,
Standard for Information Technology -- Portable Operating System
Interface (POSIX), The Open Group Base Specifications Issue 6,
Copyright (C) 2001-2004 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy
between these versions and the original IEEE and The Open Group
Standard, the original IEEE and The Open Group Standard is the referee
document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html.
This notice shall appear on any product containing this material.
The contents of this file are subject to the terms of the
Common Development and Distribution License (the "License").
You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
or http://www.opensolaris.org/os/licensing.
See the License for the specific language governing permissions
and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each
file and include the License file at usr/src/OPENSOLARIS.LICENSE.
If applicable, add the following below this CDDL HEADER, with the
fields enclosed by brackets "[]" replaced with your own identifying
information: Portions Copyright [yyyy] [name of copyright owner]
Copyright 1989 AT&T
Copyright (c) 1992, X/Open Company Limited. All Rights Reserved.
Portions Copyright (c) 2006, Sun Microsystems, Inc. All Rights Reserved.
/usr/bin/file [-bdh] [-m mfile] [-M Mfile] [-f ffile] file...
/usr/bin/file [-bdh] [-m mfile] [-M Mfile] -f ffile
/usr/bin/file -i [-bh] [-f ffile] file...
/usr/bin/file -i [-bh] -f ffile
/usr/bin/file -c [-d] [-m mfile] [-M Mfile]
/usr/xpg4/bin/file [-bdh] [-m mfile] [-M Mfile] [-f ffile] file...
/usr/xpg4/bin/file [-bdh] [-m mfile] [-M Mfile] -f ffile
/usr/xpg4/bin/file -i [-bh] [-f ffile] file...
/usr/xpg4/bin/file -i [-bh] -f ffile
/usr/xpg4/bin/file -c [-d] [-m mfile] [-M Mfile]
The file utility performs a series of tests on each file supplied by file and, optionally, on each file listed in ffile in an attempt to classify it. If the file is not a regular file, its file type is identified. The file types directory, FIFO, block special, and character special are identified as such. If the file is a regular file and the file is zero-length, it is identified as an empty file.
If file appears to be a text file, file examines the first 512 bytes and tries to determine its programming language. If file is a symbolic link, by default the link is followed and file tests the file to which the symbolic link refers.
If file is a relocatable object, executable, or shared object, file prints out information about the file's execution requirements. This information includes the machine class, byte-ordering, static/dynamic linkage, and any software or hardware capability requirements. If file is a runtime linking configuration file, file prints information about the target platform, including the machine class and byte-ordering.
By default, file will try to use the localized magic file /usr/lib/locale/locale/LC_MESSAGES/magic, if it exists, to identify files that have a magic number. For example, in the Japanese locale, file will try to use /usr/lib/locale/ja/LC_MESSAGES/magic. If a localized magic file does not exist, file will utilize /etc/magic. A magic number is a numeric or string constant that indicates the file type. See magic(5) for an explanation of the format of /etc/magic.
If file does not exist, cannot be read, or its file status could not be determined, it is not considered an error that affects the exit status. The output will indicate that the file was processed, but that its type could not be determined.
The following options are supported: -b
Be brief, do not print leading filename.
Checks the magic file for format errors. For reasons of efficiency, this validation is normally not carried out.
Applies any position-sensitive and context-sensitive default system tests to the file.
ffile contains a list of the files to be examined.
When a symbolic link is encountered, this option identifies the file as a symbolic link. If -h is not specified and file is a symbolic link that refers to a non-existent file, the file utility identifies the file as a symbolic link, as if -h had been specified.
If a file is a regular file, this option does not attempt to classify the type of file further, but identifies the file as a "regular file".
Specifies the name of a file containing position-sensitive tests that are applied to a file in order to classify it (see magic(5)). If the -m option is specified without specifying the -d option or the -M option, position-sensitive default system tests are applied after the position-sensitive tests specified by the -m option.
Specifies the name of a file containing position-sensitive tests that are applied to a file in order to classify it (see magic(5)). No position-sensitive default system tests nor context-sensitive default system tests are applied unless the -d option is also specified.
If the -M option is specified with the -d option, the -m option, or both, or if the -m option is specified with the -d option, the concatenation of the position-sensitive tests specified by these options is applied in the order specified by the appearance of these options.
The following operands are supported: file
A path name of a file to be tested.
See largefile(7) for the description of the behavior of file when encountering files greater than or equal to 2 Gbyte ( 2^31 bytes).
Example 1 Determining if an Argument is a Binary Executable Files
The following example determine if an argument is a binary executable file:
file "$1" | grep -Fq executable && printf "%s is executable.\en" "$1"
See environ(7) for descriptions of the following environment variables that affect the execution of file: LANG, LC_ALL, LC_CTYPE, LC_MESSAGES, and NLSPATH.
The following exit values are returned: 0
Successful completion.
An error occurred.
file's magic number file
See attributes(7) for descriptions of the following attributes:
| ATTRIBUTE TYPE ATTRIBUTE VALUE |
| CSI Enabled |
| Interface Stability Standard |
crle (1), elfdump (1), ls (1), magic (5), attributes (7), environ (7), largefile (7), standards (7)