Trash (computing)In computing, the trash is a graphical user interface desktop metaphor for temporary storage for set aside by the user for deletion, but not yet permanently erased. The concept and name is part of Mac operating systems, a similar implementation is called the Recycle Bin in Microsoft Windows, and other operating systems use other names. In the , the trash can be viewed by the user as a special file directory, allowing the user to browse the files and retain those still wanted before deleting the others permanently (either one by one, or via an "empty trash" command).
Computer fontA computer font is implemented as a digital containing a set of graphically related glyphs. A computer font is designed and created using a font editor. A computer font specifically designed for the computer screen, and not for printing, is a screen font. In the terminology of movable metal type, a font is a set of pieces of movable type in a specific typeface, size, width, weight, slope, etc. (for example, Gill Sans bold 12 point or Century Expanded 14 point), and a typeface refers to the collection of related fonts across styles and sizes (for example, all the varieties of Gill Sans).
Pipeline (Unix)In Unix-like computer operating systems, a pipeline is a mechanism for inter-process communication using message passing. A pipeline is a set of processes chained together by their standard streams, so that the output text of each process (stdout) is passed directly as input (stdin) to the next one. The second process is started as the first process is still executing, and they are executed concurrently. The concept of pipelines was championed by Douglas McIlroy at Unix's ancestral home of Bell Labs, during the development of Unix, shaping its toolbox philosophy.
PowerShellPowerShell is a task automation and configuration management program from Microsoft, consisting of a command-line shell and the associated scripting language. Initially a Windows component only, known as Windows PowerShell, it was made open-source and cross-platform on August 18, 2016, with the introduction of PowerShell Core. The former is built on the .NET Framework, the latter on .NET (previously .NET Core). Since Windows 10 build 14971, PowerShell replaced Command Prompt and became the default command shell for .
Rm (Unix)rm (short for remove) is a basic command on Unix and Unix-like operating systems used to remove objects such as s, directories and symbolic links from s and also such as device nodes, pipes and sockets, similar to the del command in MS-DOS, OS/2, and Microsoft Windows. The command is also available in the EFI shell. The rm command removes references to objects from the filesystem using the unlink system call, where those objects might have had multiple references (for example, a file with two different names), and the objects themselves are discarded only when all references have been removed and no programs still have open handles to the objects.
Multiuser DOSMultiuser DOS is a real-time multi-user multi-tasking operating system for IBM PC-compatible microcomputers. An evolution of the older Concurrent CP/M-86, Concurrent DOS and Concurrent DOS 386 operating systems, it was originally developed by Digital Research and acquired and further developed by Novell in 1991. Its ancestry lies in the earlier Digital Research 8-bit operating systems CP/M and MP/M, and the 16-bit single-tasking CP/M-86 which evolved from CP/M.
Comparison of command shellsA command shell is a command-line interface to interact with and manipulate a computer's operating system. Background execution allows a shell to run a command without user interaction in the terminal, freeing the command line for additional work with the shell. POSIX shells and other Unix shells allow background execution by using the & character at the end of command. In PowerShell, the Start-Process or Start-Job cmdlets can be used.
Batch fileA batch file is a script file in DOS, OS/2 and Microsoft Windows. It consists of a series of commands to be executed by the command-line interpreter, stored in a plain text file. A batch file may contain any command the interpreter accepts interactively and use constructs that enable conditional branching and looping within the batch file, such as IF, FOR, and GOTO labels. The term "batch" is from batch processing, meaning "non-interactive execution", though a batch file might not process a batch of multiple data.
Entry pointIn computer programming, an entry point is the place in a program where the execution of a program begins, and where the program has access to command line arguments. To start a program's execution, the loader or operating system passes control to its entry point. (During booting, the operating system itself is the program). This marks the transition from load time (and dynamic link time, if present) to run time. For some operating systems and programming languages, the entry point is in a runtime library, a set of support functions for the language.
Del (command)In computing, del (or erase) is a command in command-line interpreters (shells) such as COMMAND.COM, cmd.exe, 4DOS, NDOS, 4OS2, 4NT and Windows PowerShell. It is used to delete one or more or from a . The command is available for various operating systems including DOS, Microware OS-9, IBM OS/2, Microsoft Windows and ReactOS. It is analogous to the Unix rm command and to the Stratus OpenVOS delete_file and delete_dircommands. DEC RT-11, OS/8, RSX-11, and OpenVMS also provide the delete command which can be contracted to del.
Help (command)In computing, help is a command in various command line shells such as COMMAND.COM, cmd.exe, Bash, qshell, 4DOS/4NT, Windows PowerShell, Singularity shell, Python, MATLAB and GNU Octave. It provides online information about available commands and the shell environment. The command is available in operating systems such as Multics, Heath Company HDOS, CP/M Plus, DOS, IBM OS/2, eComStation, ArcaOS, IBM i, Microsoft Windows, ReactOS, THEOS/OASIS, Zilog Z80-RIO, Microware OS-9, Stratus OpenVOS, HP MPE/iX, Motorola VERSAdos, KolibriOS and also in the DEC RT-11, RSX-11, TOPS-10 and TOPS-20 operating systems.
Rcrc (for "run commands") is the command line interpreter for Version 10 Unix and Plan 9 from Bell Labs operating systems. It resembles the Bourne shell, but its syntax is somewhat simpler. It was created by Tom Duff, who is better known for an unusual C programming language construct ("Duff's device"). A port of the original rc to Unix is part of Plan 9 from User Space. A rewrite of rc for Unix-like operating systems by Byron Rakitzis is also available but includes some incompatible changes.
Copy (command)In computing, copy is a command in various operating systems. The command s from one directory to another. Generally, the command copies files from one location to another. It is used to make copies of existing files, but can also be used to combine (concatenate) multiple files into target files. The destination defaults to the current working directory. If multiple source files are indicated, the destination must be a directory, or an error will result.
EmacsEmacs ˈiːmæks, originally named EMACS (an acronym for "Editor MACroS"), is a family of text editors that are characterized by their extensibility. The manual for the most widely used variant, GNU Emacs, describes it as "the extensible, customizable, self-documenting, real-time display editor". Development of the first Emacs began in the mid-1970s, and work on its direct descendant, GNU Emacs, is ongoing; its latest version is 29.1, released July 2023.
EmulatorIn computing, an emulator is hardware or software that enables one computer system (called the host) to behave like another computer system (called the guest). An emulator typically enables the host system to run software or use peripheral devices designed for the guest system. Emulation refers to the ability of a computer program in an electronic device to emulate (or imitate) another program or device. Many printers, for example, are designed to emulate HP LaserJet printers because so much software is written for HP printers.
PATH (variable)PATH is an environment variable on Unix-like operating systems, DOS, OS/2, and Microsoft Windows, specifying a set of where executable programs are located. In general, each executing process or user session has its own PATH setting. Multics originated the idea of a search path. The early Unix shell only looked for program names in /bin, but by Version 3 Unix the directory was too large and /usr/bin, and a search path, became part of the operating system.
Enter keyOn computer keyboards, the enter key and return key are two closely related keys with overlapping and distinct functions dependent on operating system and application. The return key has its origins in two typewriter functions: carriage return, which would reset the carriage to the beginning of the line of text, and line feed, which would advance the paper one line downward. These were often combined into a single return key, a convention that continues in modern computer word processing to insert a paragraph break (¶).
Read–eval–print loopA read–eval–print loop (REPL), also termed an interactive toplevel or language shell, is a simple interactive computer programming environment that takes single user inputs, executes them, and returns the result to the user; a program written in a REPL environment is executed piecewise. The term usually refers to programming interfaces similar to the classic Lisp machine interactive environment. Common examples include command-line shells and similar environments for programming languages, and the technique is very characteristic of scripting languages.
Cursor (user interface)In human–computer interaction, a cursor is an indicator used to show the current position on a computer monitor or other display device that will respond to input. Cursor is Latin for 'runner'. A cursor is a name given to the transparent slide engraved with a hairline used to mark a point on a slide rule. The term was then transferred to computers through analogy.
MS-DOSMS-DOS (ˌɛmˌɛsˈdɒs ; 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 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).
