In many versions of DOS (MS-DOS/PC DOS 2.xx and higher, all versions of DR-DOS since 5.0, as well as PTS-DOS, Embedded DOS, FreeDOS and RxDOS) the switch character (sometimes abbreviated switchar or switchchar) to be used is defined by a value returned from a system call (INT 21h/AH=37h). [18], Depending on the program, additional or more specific help on accepted parameters is sometimes available by either providing the parameter in question as an argument to the help parameter or vice versa (as in /H:W or in /W:? For example, in the following command the options indicate that the target file should be replaced if it exists, and the date and time of the source file should be retained on the copy: If you want to report an error, or if you want to make a suggestion, do not hesitate to send us an e-mail: W3Schools is optimized for learning and training. If more detailed help is necessary than provided by a program's built-in internal help, many systems support a dedicated external "help command" command (or similar), which accepts a command name as calling parameter and will invoke an external help system. Includes Top... Read More », Have you heard about a computer certification program but can't figure out if it's right for you? In Unix-like systems, the ASCII hyphen-minus begins options; the new (and GNU) convention is to use two hyphens then a word (e.g. 'Command Line Interface' is one option -- get in to view more @ The Web's largest and most authoritative acronyms and abbreviations resource. Ambiguity can be prevented either by prohibiting embedded spaces in file and directory names in the first place (for example, by substituting them with underscores _), or by enclosing a name with embedded spaces between quote characters or using an escape character before the space, usually a backslash (\). The syntax is the grammar that all commands must follow. In RISC OS the command prompt is a * symbol, and thus (OS)CLI commands are often referred to as "star commands". The early Sierra games, such as the first three King's Quest games (1984–1986), used commands from an internal command line to move the character around in the graphic window. Early microcomputers themselves were based on a command-line interface such as CP/M, DOS or AppleSoft BASIC. Early computer systems often used teleprinter machines as the means of interaction with a human operator.

Many video games on the PC feature a command line interface often referred to as a console. display in long format files and directories beginning with "D" (but not "d"), sorted by size (largest first).
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In the 1970s an 1980s, command line input was commonly used by Unix systems and PC systems like MS-DOS and Apple DOS. Unix also had the capability to save and re-run strings of commands as "shell scripts" which acted like custom commands. (2) Short for Common Language Infrastructure. --create) to identify the option's use while the old convention (and still available as an option for frequently-used options) is to use one hyphen then one letter (e.g., -c); if one hyphen is followed by two or more letters it may mean two options are being specified, or it may mean the second and subsequent letters are a parameter (such as filename or date) for the first option. The default of older DOS systems, C> is obtained by just PROMPT, although on some systems this produces the newer C:\> style, unless used on floppy drives A: or B:; on those systems PROMPT $N$G can be used to override the automatic default and explicitly switch to the older style. Recovers readable information from a bad or defective disk. In the 1960s, using only computer terminals, this was the only way to interact with computers. This is a common feature of GNU software. Two different CLIs may agree on either syntax or semantics, but it is only when they agree on both that they can be considered sufficiently similar to allow users to use both CLIs without needing to learn anything, as well as to enable re-use of scripts. Programs with command-line interfaces are generally easier to automate via scripting. [25][better source needed].