You can enter a command by using the keyboard. Some commands also have abbreviated names called command aliases.
To enter a command by using the keyboard, type the full command name or its command alias in the input area of the Command Line, and then press Enter or Spacebar. The Command Line includes several controls.
By default, AutoCAD automatically completes the name of a command or system variable as you type it. Additionally, a list of valid choices is displayed from which you can choose. Use the AUTOCOMPLETE command to control which automatic features that you want to use.
If the automatic completion feature turned off, you can type a letter on the command line and press TAB to cycle through all the commands and system variables that begin with that letter. Press Enter or Spacebar to start the command or system variable.
Some commands also have alternate names. For example, instead of entering circle to start the CIRCLE command, you can enter c. Command aliases are defined in the acad.pgp file.
To define your own command aliases, see Create Command Aliases in the Customization Guide.
When you enter a command in the Command Line, you see either a set of options, a dialog box, or a palette. To specify an option displayed in the Command line, enter the capitalized letters for the option. For example, when you enter circle, the following prompt is displayed:
Specify center point for circle or [3P/2P/Ttr (tan tan radius)]:
You can specify the center point for the circle either by entering X,Y coordinate values, or by using the pointing device to click a point in the drawing area.
To choose a different option, enter the letters capitalized in one of the options in the brackets. You can enter uppercase or lowercase letters. For example, to choose the three-point option (3P), enter 3p.
You can repeat the previous command by pressing Enter or Spacebar.
To repeat a recently used command, right-click in the Command Line or click the drop-down arrow to the left of the command input area. This action displays a shortcut menu with a list of recently used commands.
You can also repeat a recently used command by cycling through the commands with Up Arrow and Down Arrow keys, and then pressing Enter.
To cancel any command in progress, press ESC.