Command-line interface

The command line, command line or from the English command- line interface, short CLI, often referred to as a console or terminal, an input region ( interface) for the control of software which runs typically (but not necessarily) in text mode. Depending on the operating system command line of a shell or a command line interpreter ( also abbreviated in English interpreter with CLI for command- line - the abbreviation thus has two meanings ) evaluated and the corresponding function.

The command or commands are entered as a string from the keyboard, often they are taken from the English, partly as an abbreviation such as in MS -DOS command you. Directory or for Unix systems, the ls command to list directory

The execution of commands is mostly controlled directly from the line by additionally specified parameter (command line parameters). Programs that ask the user interactively, are rather uncommon at this level. A command line program therefore typically runs with the given parameters even from before a new command input is possible. An automated processing of multiple commands is called batch processing ( batch).


A command-line interpreter, such as bash, csh, zsh, Windows PowerShell, cmd.exe or COMMAND.COM, typically can also provide a command line.

Command lines are integrated into not pure CLI applications. In the mathematical software MATLAB, it is however an important part of the otherwise graphical interface. Also file manager like Midnight Commander usually have integrated a shell, but are de facto in the category of character-based user interfaces. Also debugger often offer a combination of command line and other elements to control them. Special variants of the command line can be found in FTP client programs for the text mode. Some telnet clients provide only the actual functionality of a additional command line to control that is typically accessed via a so-called escape key combination.

Games from the PC sector, or more precisely, the underlying game engines, often offer command line. Usually hidden and not necessary for the actual games, they allow an alternative configuration or profound influence on the game. It simplifies the development testing of program code and allows selected individual states troubleshooting reach, as well as the input of cheat commands by players. An example of such a panel is in the quake engine.

For X11, there are a number of graphical terminal emulators such as xterm, aterm, Eterm or rxvt. The Unix Gnome desktop environment is Gnome Terminal, KDE, there is the console. These terminal emulators offer itself not a command line to, in them rather runs one of the above mentioned command line interpreter like bash, etc.

Input process

Technically, the command line is a service offered by a program command line, which is equipped with a certain amount of skill editor. The entry is completed by pressing the Enter key. This causes the sending of carriage return or line feed character to the program, which has opened the entry line. In response, the user-entered command line text is interpreted; the command line interpreter leads for error-free detection of input from the appropriate commands, right then bring their eventual expenditure on the screen. After a re- prompt sequence which indicates that the input of another command line is possible appears.

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A comparison of the shells of three major operating systems