LOCKDEV
LOCKDEV
NAMESYNOPSIS
DESCRIPTION
RETURN VALUES
SEE ALSO
NAME
Lockdev is a setgid binary, which provides a reliable way to put an exclusive lock in /var/lock to devices (e.g. ttyS0) using both FSSTND and SVr4 methods, so regular users don’t need write access there.
This task is achieved through calls to the liblockdev(3) API.
SYNOPSIS
/usr/sbin/lockdev [<operation>] <device>
DESCRIPTION
The lockdev command can perform one of the following operations (calls to liblockdev(3) API):
-l - lock device with dev_lock() function
-u - unlock device with dev_unlock() function
no operation - test lock with dev_testlock() function
RETURN VALUES
Value dev_lock
dev_unlock dev_testlock
0 OK OK not locked
1 locked other locked other locked
2 EACCES
3 EROFS
4 EFAULT
5 EINVAL
6 ENAMETOOLONG
7 ENOENT
8 ENOTDIR
9 ENOMEM
10 ELOOP
11 EIO
12 EPERM
255 error error error
SEE ALSO
lockdev(3).
Opportunity
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
Free Books
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Education
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.
