Command-line interface

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 mode available with punched cards.^[1]

Today, most computer users rely on graphical user interfaces ("GUIs") instead of CLIs. However, many programs and operating system utilities lack GUIs, and are intended to be used through CLIs.

Knowledge of CLIs is also useful for automation of programs via the writing of scripts. Automation is a more accessible option for programs that have CLIs, in contrast to purely graphical UI's, since many individual commands can be described together into single files called scripts. Executed individually as programs in their own right, scripts allow the group of CLI commands that they contain to be executed at the same time as a single batch of commands.

CLIs are made possible by command-line interpreters or command-line processors, which are programs that read command lines and carry out the commands.

Alternatives to CLIs include GUIs (most notably desktop metaphors with a mouse pointer, such as Microsoft Windows), text-based user interface menus (such as DOS Shell and IBM AIX SMIT), and keyboard shortcuts.