Command-line interfaceA command-line interface (CLI), also known as a command-line shell, is a means of interacting with software via commands – each formatted as a line of text. The concept of interacting with a computer via text evolved over two decades, transitioning from physical hardware to sophisticated software. Before the CLI, computers were programmed using physical switches or punched cards. The shift toward a "command" style interaction began with the use of Teleprinters (Teletypes).
Operating systemSoftware that manages computer hardware resourcesAn operating system (OS) is system software that manages computer hardware and software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, peripherals, and other resources.
Computer programA computer program is a sequence or set of instructions in a programming language for a computer to execute. It is one component of software, which also includes documentation and other intangible components. A computer program in its human-readable form is called source code. Source code needs another computer program to execute because computers can only execute their native machine instructions.
Stream (computing)In computer science, a stream is a sequence of potentially unlimited data elements made available over time. A stream can be thought of as items on a conveyor belt being processed one at a time rather than in large batches. Streams are processed differently from batch data. Normal functions cannot operate on streams as a whole because they have potentially unlimited data. Formally, streams are codata (potentially unlimited), not data (which is finite).
MS-DOSMicrosoft computer operating systemOperating systemMS-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 alternate branding as IBM PC DOS, and a few operating systems attempting to be compatible with MS-DOS, are sometimes referred to as "DOS" (which is also the generic acronym for disk operating system).
Windows 72009 Microsoft operating system versionOperating systemWindows 7 is a major release of the Windows NToperating system developed by Microsoft. It was released to manufacturing on July 22, 2009, and became generally available on October 22, 2009. It is the successor to Windows Vista, released nearly three years earlier. Windows 7's server counterpart, Windows Server 2008 R2, was released at the same time.Pipeline (software)In software engineering, a pipeline consists of a chain of processing elements (processes, threads, coroutines, functions, etc.), arranged so that the output of each element is the input of the next. The concept is analogous to a physical pipeline. Usually some amount of buffering is provided between consecutive elements. The information that flows in these pipelines is often a stream of records, bytes, or bits, and the elements of a pipeline may be called filters.Cmd.execmd.exe, also known as Command Prompt or Windows Command Processor, is a shell program on later versions of Windows (NT and CE families), OS/2, eComStation, ArcaOS, and ReactOS. In some versions of Windows (CE .NET 4.2, CE 5.0 and Embedded CE 6.0) it is referred to as the Command Processor Shell. Implementation differs between operating systems, but with significant consistency of behavior and available commands.
PowerShellCross-platform shell based on .NET technologyPowerShell is a shellprogram developed by Microsoft for task automation and configuration management. As is typical for a shell, it provides a command-lineinterpreter for interactive use and a script interpreter for automation via a language defined for it. Originally only for Windows, known as Windows PowerShell, it was made open-source and cross-platform on August 18, 2016, with the introduction of PowerShell Core.
UnixUnix ( , YOO-niks; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, the development of which started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others.
MacOSmacOS (previously OS X and originally Mac OS X) is a proprietary Unix operating system, derived from OPENSTEP for Mach and FreeBSD, which has been marketed and developed by Apple since 2001. It is the current operating system for Apple's line of Mac computers. As of April 2026, within the market of desktop and laptop computers, it is the second most widely used desktop OS, after Microsoft Windows and ahead of all Linux distributions, including ChromeOS and SteamOS.
Function (computer programming)In computer programming, a function (also procedure, method, subroutine, routine, or subprogram) is a callable unit of software logic that has a well-formed interface and behavior and can be invoked multiple times. Callable units provide a powerful programming tool. The primary purpose is to enable the decomposition of a large and/or complicated problem into chunks that have relatively low cognitive load.*As an Amazon Associate I earn from qualifying purchases.