Cygwin is a free and open-source Unix-like environment and command-line interface (CLI) for Microsoft Windows. The project also provides a software repository containing many open-source packages. Cygwin allows source code for Unix-like operating systems to be compiled and run on Windows. Cygwin provides native integration of Windows-based applications.
A graphical user interface, or GUI, is a form of user interface that allows users to interact with electronic devices through graphical icons and visual indicators such as secondary notation. In many applications, GUIs are used instead of text-based UIs, which are based on typed command labels or text navigation. GUIs were introduced in reaction to the perceived steep learning curve of command-line interfaces (CLIs), which require commands to be typed on a computer keyboard.
The history of the graphical user interface, understood as the use of graphic icons and a pointing device to control a computer, covers a five-decade span of incremental refinements, built on some constant core principles. Several vendors have created their own windowing systems based on independent code, but with basic elements in common that define the WIMP "window, icon, menu and pointing device" paradigm.
Scroll Lock is a lock key on most IBM-compatible computer keyboards. Depending on the operating system, it may be used for different purposes, and applications may assign functions to the key or change their behavior depending on its toggling state. The key is not frequently used, and therefore some reduced or specialized keyboards lack Scroll Lock altogether.
Computer operating systems (OSes) provide a set of functions needed and used by most application programs on a computer, and the links needed to control and synchronize computer hardware. On the first computers, with no operating system, every program needed the full hardware specification to run correctly and perform standard tasks, and its own drivers for peripheral devices like printers and punched paper card readers. The growing complexity of hardware and application programs eventually made operating systems a necessity for everyday use.
A computer terminal is an electronic or electromechanical hardware device that can be used for entering data into, and transcribing data from, a computer or a computing system. Most early computers only had a front panel to input or display bits and had to be connected to a terminal to print or input text through a keyboard. Teleprinters were used as early-day hard-copy terminals and predated the use of a computer screen by decades. The computer would typically transmit a line of data which would be printed on paper, and accept a line of data from a keyboard over a serial or other interface. Starting in the mid-1970s with microcomputers such as the Sphere 1, Sol-20, and Apple I, display circuitry and keyboards began to be integrated into personal and workstation computer systems, with the computer handling character generation and outputting to a CRT display such as a computer monitor or, sometimes, a consumer TV, but most larger computers continued to require terminals.
In computing, text-based user interfaces (TUI), is a retronym describing a type of user interface (UI) common as an early form of human–computer interaction, before the advent of bitmapped displays and modern conventional graphical user interfaces (GUIs). Like modern GUIs, they can use the entire screen area and may accept mouse and other inputs. They may also use color and often structure the display using box-drawing characters such as ┌ and ╣. The modern context of use is usually a terminal emulator.
Text mode is a computer display mode in which content is internally represented on a computer screen in terms of characters rather than individual pixels. Typically, the screen consists of a uniform rectangular grid of character cells, each of which contains one of the characters of a character set; at the same time, contrasted to graphics mode or other kinds of computer graphics modes.
In some operating systems, including Unix-like systems, a pseudoterminal, pseudotty, or PTY is a pair of pseudo-device endpoints (files) which establish asynchronous, bidirectional communication (IPC) channel between two or more processes.
A virtual console (VC) – also known as a virtual terminal (VT) – is a conceptual combination of the keyboard and display for a computer user interface. It is a feature of some Unix-like operating systems such as Linux, BSD, illumos, UnixWare, and macOS in which the system console of the computer can be used to switch between multiple virtual consoles to access unrelated user interfaces. Virtual consoles date back at least to Xenix and Concurrent CP/M in the 1980s.
A console application or command-line program is a computer program designed to be used via a text-only user interface, such as a text terminal, the command-line interface of some operating systems or the text-based interface included with most graphical user interface (GUI) operating systems, such as the Windows Console in Microsoft Windows, the Terminal in macOS, and xterm in Unix.
In telecommunications, echo is the local display of data, either initially as it is locally sourced and sent, or finally as a copy of it is received back from a remote destination. Local echo is where the local sending equipment displays the outgoing sent data. Remote echo is where the display is a return copy of data as received remotely. Both are used together in a computed form of error detection to ensure that data received at the remote destination of a telecommunication are the same as data sent from the local source. When (two) modems communicate in echoplex mode the remote modem echoes whatever it receives from the local modem.
In Unix-like operating systems, a device file, device node, or special file is an interface to a device driver that appears in a file system as if it were an ordinary file. There are also special files in DOS, OS/2, and Windows. These special files allow an application program to interact with a device by using its device driver via standard input/output system calls. Using standard system calls simplifies many programming tasks, and leads to consistent user-space I/O mechanisms regardless of device features and functions.
A headless computer is a computer system or device that has been configured to operate without a monitor, keyboard, and mouse. A headless system is typically controlled over a network connection, although some headless system devices require a serial connection to be made over RS-232 for administration of the device. Headless operation of a server is typically employed to reduce operating costs.
The Linux console is a system console internal to the Linux kernel. A system console is the device which receives all kernel messages and warnings and which allows logins in single user mode. The Linux console provides a way for the kernel and other processes to send text output to the user, and to receive text input from the user. The user typically enters text with a computer keyboard and reads the output text on a computer monitor. The Linux kernel supports virtual consoles – consoles that are logically separate, but which access the same physical keyboard and display. The Linux console are implemented by the VT subsystem of the Linux kernel, and do not rely on any user space software. This is in contrast to a terminal emulator, which is a user space process that emulates a terminal, and is typically used in a graphical display environment.
A command-line interface (CLI) is a means of interacting with a computer program by inputting lines of text called command-lines. Command-line interfaces emerged in the mid-1960s, on computer terminals, as an interactive and more user-friendly alternative to the non-interactive interface available with punched cards.
The POSIX terminal interface is the generalized abstraction, comprising both an application programming interface for programs, and a set of behavioural expectations for users of a terminal, as defined by the POSIX standard and the Single Unix Specification. It is a historical development from the terminal interfaces of BSD version 4 and Seventh Edition Unix.
A terminal multiplexer is a software application that can be used to multiplex several separate pseudoterminal-based login sessions inside a single terminal display, terminal emulator window, PC/workstation system console, or remote login session, or to detach and reattach sessions from a terminal. It is useful for dealing with multiple programs from a command line interface, and for separating programs from the session of the Unix shell that started the program, particularly so a remote process continues running even when the user is disconnected.
devpts is a virtual filesystem directory available in the Linux kernel since version 2.1.93. It is normally mounted at /dev/pts and contains solely devices files which represent slaves to the multiplexing master located at /dev/ptmx which in turn is used to implement terminal emulators.
Comparison of user features of operating systems refers to a comparison of the general user features of major operating systems in a narrative format. It does not encompass a full exhaustive comparison or description of all technical details of all operating systems. It is a comparison of basic roles and the most prominent features. It also includes the most important features of the operating system's origins, historical development, and role.
