In
computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, e ...
,
share is a
command
Command may refer to:
Computing
* Command (computing), a statement in a computer language
* COMMAND.COM, the default operating system shell and command-line interpreter for DOS
* Command key, a modifier key on Apple Macintosh computer keyboards
* ...
for
DOS
DOS is shorthand for the MS-DOS and IBM PC DOS family of operating systems.
DOS may also refer to:
Computing
* Data over signalling (DoS), multiplexing data onto a signalling channel
* Denial-of-service attack (DoS), an attack on a communicat ...
that allows software to perform
file lock
File locking is a mechanism that restricts access to a computer file, or to a region of a file, by allowing only one user or process to modify or delete it at a specific time and to prevent reading of the file while it's being modified or deleted ...
s. Locking files became necessary when
MS-DOS
MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few ope ...
began allowing files to be accessed simultaneously by multiple programs, either through
multitasking or
networking.
Implementations
On MS-DOS, the command is available in versions 3 and later.
The command is also available in
FreeDOS
FreeDOS (formerly Free-DOS and PD-DOS) is a free software operating system for IBM PC compatible computers. It intends to provide a complete MS-DOS-compatible environment for running Legacy system, legacy software and supporting embedded system ...
,
PTS-DOS
PTS-DOS (aka PTS/DOS) is a disk operating system, a DOS clone, developed in Russia by PhysTechSoft and Paragon Technology Systems.
History and versions
PhysTechSoft was formed in 1991 in Moscow, Russia by graduates and members of MIPT, infor ...
, and
SISNE plus
SISNE plus is a DOS 3.3 compatible clone created by Itautec and Scopus Tecnologia in Brazil prior to the end of the Market Reserve in 1991, which, at that time, forbade the importation of electronic equipment and software for general use. With ...
. The FreeDOS version was developed by Ron Cemer and is licensed under the
GPL
The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general u ...
.
DR DOS 6.0
DR-DOS (written as DR DOS, without a hyphen, in versions up to and including 6.0) is a disk operating system for IBM PC compatibles. Upon its introduction in 1988, it was the first DOS attempting to be compatible with IBM PC DOS and MS-D ...
[DR DOS 6.0 User Guide Optimisation and Configuration Tips](_blank)
/ref> and Datalight
Datalight was a privately held software company specializing in power failsafe and high performance software for preserving data integrity in embedded systems. The company was founded in 1983 by Roy Sherrill, and is headquartered in Bothell, Washi ...
ROM-DOS
Datalight was a privately held software company specializing in power failsafe and high performance software for preserving data integrity in embedded systems. The company was founded in 1983 by Roy Sherrill, and is headquartered in Bothell, Washi ...
include an implementation of the command.
Windows XP
Windows XP is a major release of Microsoft's Windows NT operating system. It was released to manufacturing on August 24, 2001, and later to retail on October 25, 2001. It is a direct upgrade to its predecessors, Windows 2000 for high-end and ...
and later versions include 16-bit
16-bit microcomputers are microcomputers that use 16-bit microprocessors.
A 16-bit register can store 216 different values. The range of integer values that can be stored in 16 bits depends on the integer representation used. With the two mos ...
commands (nonnative) for the MS-DOS subsystem that are included to maintain MS-DOS compatibility. The share MS-DOS subsystem command performs functions that are now inherent to Microsoft Windows
Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...
. It is available to preserve compatibility with existing files, but has no effect at the command line
A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and pro ...
because the functionality is automatic. The 16-bit MS-DOS subsystem commands are not available on 64-bit
In computer architecture, 64-bit Integer (computer science), integers, memory addresses, or other Data (computing), data units are those that are 64 bits wide. Also, 64-bit central processing unit, CPUs and arithmetic logic unit, ALUs are those ...
editions of Windows.MS-DOS subsystem commands
/ref>
Design
There were five locking modes:
*Deny None
*Deny Read
*Deny Write
*Deny All
*Compatibility (designed for backward compatibility
Backward compatibility (sometimes known as backwards compatibility) is a property of an operating system, product, or technology that allows for interoperability with an older legacy system, or with input designed for such a system, especially i ...
with existing MS-DOS programs)
The program runs as a Terminate and Stay Resident
A terminate-and-stay-resident program (commonly TSR) is a computer program running under DOS that uses a system call to return control to DOS as though it has finished, but remains in computer memory so it can be reactivated later. This technique ...
program and is typically loaded at boot-up.
Syntax
share F:space L:locks
*/F:space Allocates file space (in bytes) for file-sharing information.
*/L:locks Sets the number of files that can be locked at one time.
See also
*List of DOS commands
This article presents a list of commands used by DOS operating systems, especially as used on x86-based IBM PC compatibles (PCs). Other DOS operating systems are not part of the scope of this list.
In DOS, many standard system commands were pro ...
References
Further reading
*
External DOS commands
{{DOS-stub