Linux/CentOS's file command

Dùng tốt ;) Hơi ngạc nhiên file "file" command chạy ngon với closed format .xls như thế

$file ReleaseNote.xls
ReleaseNote.xls:
- CDF V2 Document,
- Little Endian,
- Os: Windows,
- Version 6.1,
- Code page: 932,
- Author: <author name>,
- Last Saved By: <username>,
- Name of Creating Application: Microsoft Excel,
- Create Time/Date: Thu Feb  7 05:42:19 2013,
- Last Saved Time/Date: Thu Feb  7 06:58:20 2013,
- Security: 0

$  which file
/usr/bin/file

$  rpm -qf `which file`
file-5.04-13.el6.i686

$  rpm -qi file
Name        : file                         Relocations: (not relocatable)
Version     : 5.04                              Vendor: CentOS
Release     : 13.el6                        Build Date: Thu 15 Mar 2012 04:35:33 PM ICT
Install Date: Tue 10 Jul 2012 11:37:42 AM ICT      Build Host: c6b5.bsys.dev.centos.org
Group       : Applications/File             Source RPM: file-5.04-13.el6.src.rpm
Size        : 53871                            License: BSD
Signature   : RSA/SHA1, Thu 15 Mar 2012 04:50:32 PM ICT, Key ID 0946fca2c105b9de
Packager    : CentOS BuildSystem <http://bugs.centos.org>
URL         : http://www.darwinsys.com/file/
Summary     : A utility for determining file types
Description :
The file command is used to identify a particular file according to the
type of data contained by the file.  File can identify many different
file types, including ELF binaries, system libraries, RPM packages, and
different graphics formats.
$  cat /etc/redhat-release
CentOS release 6.3 (Final)

--   Best Regards,  Nguyen Hung Vu [aka: NVH] (in Vietnamese: Nguyễn Vũ Hưng, グェン　ヒュン　ウー, 阮武興)  vuhung16plus{remove}@gmail.dot.com , YIM: vuhung16 , Skype:  vuhung16plus, twitter: vuhung, MSN: vuhung16.  http://www.facebook.com/nguyenvuhung  Nguyễn Vũ Hưng's blog on Free and Open Source:  http://nguyenvuhungvietnam.wordpress.com/  Học tiếng Nhật: http://hoc-tiengnhat.blogspot.com/  Vietnamese LibreOffice: http://libo-vi.blogspot.com/  Mozilla & Firefox tiếng Việt: http://mozilla-vi.blogspot.com/    Disclaimer: When posted to social networking groups include, but not limited Linux Users' Groups,  Free and Open Sources forums, mailing lists, the above is my personal opinion and is *not*  the opinion of my employer(s), associations and/or groups I join.