by Dinesh Thakur

In operating systems like DOS and Unix, and in many text-based or character mode programs, you control what's happening by typing commands on a command line. The command line is simply the line on the screen where you type your commands. The only way to control an operating system or a program that uses a command line interface like this is by typing commands-you don't get menus, dialog boxes, or buttons.


Command line interface a type of user interface employed by older, non-graphical computer operating systems, consisting of a COMMAND PROMPT symbol next to which the user must type in a command word and then press the Enter key, where upon the computer executes that command. Both UNIX and MSDOS employ command line interfaces.


Command line user interfaces are extremely intimidating for new users, because they do not typically list all the commands available (which have to be memorized) and any misspelling of a command will prevent it from being executed, often producing a cryptic error message. A MENU (as used in GRAPHICAL USER INTERFACES) overcomes both problems by showing what commands are available and removing the need to type them. Some menu-driven programs provide an alternative CLI for experienced users.