AutoCAD has a ribbon, menus and toolbars, yet fast drafters work almost entirely from the keyboard: type a few letters, press Enter, read what AutoCAD asks and answer. Knowing how to enter commands in AutoCAD properly speeds drawing up considerably and avoids those moments when the program seems not to listen.
This article covers reading a prompt, seven everyday techniques, and getting the command line back when it disappears. Every prompt quoted is verbatim from the 2027 release. To learn properly from the start, the Institute runs an AutoCAD course for construction.
Full names or aliases
The first way to enter a command is to type its name and press Enter: LINE, CIRCLE, TRIM. The faster way is an alias defined in the acad.pgp file: L for LINE, C for CIRCLE, TR for TRIM. Type L and Enter and the command line shows LINE and asks for the first point.
Type a wrong name and AutoCAD answers verbatim:
Unknown command "XYZABC". Press F1 for help.Nothing changes; just type it again correctly.
A few aliases read straight from the 2027 acad.pgp, for commands covered on this site:
| Alias | Command | What it does |
|---|---|---|
DI | DIST | Measures distance and angle |
MA | MATCHPROP | Copies properties from one object to others |
PRINT | PLOT | Opens the Plot dialog |
DX | DATAEXTRACTION | Extracts drawing data to a table or file |
CLI | COMMANDLINE | Shows the command line |
SL | SLICE | Slices a 3D solid |
SU | SUBTRACT | Subtracts one solid or region from another |
Aliases save a few keystrokes each time, which adds up over a working day. Aliases, and how to add or edit them, are covered in our article on command aliases.
Reading a prompt: three parts
Once a command starts, AutoCAD asks with a prompt. Take CIRCLE as the example.
Specify center point for circle or [3P/2P/Ttr (tan tan radius)]:| Part | Meaning | What you do |
|---|---|---|
Specify center point for circle | The default action AutoCAD is waiting for | Pick a point or type coordinates |
[3P/2P/Ttr (tan tan radius)] | Other options | Type the capital letters of an option, e.g. 2P |
<...> if present | The default value | Press Enter to accept it |
Type 2P there and AutoCAD switches to a circle through two ends of a diameter, then asks for the two points.
Specify first end point of circle's diameter: 0,3000
Specify second end point of circle's diameter: 1000,3000Enter, Space and Esc
These three keys do most of the work:
| Key | Effect |
|---|---|
| Enter | Confirms an answer; ends a command waiting for more points |
Enter at an empty Command: prompt | Repeats the last command |
| Space | Acts as Enter when typing command names and coordinates |
| Esc | Cancels the running command |
Typing LINE 0,1000 1000,1000 followed by two spaces draws exactly one line and ends the command, just as Enter would. Space is handy because the thumb always rests on it.
Repeating with Enter is a habit worth building early. After drawing a segment with LINE, press Enter at the empty Command: prompt and LINE starts again straight away.
Transparent commands: running a command inside another
Halfway through a line you need to zoom in to pick accurately. No need to cancel: type an apostrophe before the command name, such as 'ZOOM. The prompt gains a >> at the start, showing you are inside a nested command.
There is a trap. While drawing a line, type 'ZOOM and choose E (Extents), and the 2027 release replies:
>>Specify corner of window, enter a scale factor (nX or nXP), or
[All/Center/Dynamic/Extents/Previous/Scale/Window/Object] <real time>: E
** Requires a regen, cannot be transparent.
Resuming LINE command.Options that force a full regeneration cannot run transparently. AutoCAD says so and returns to the unfinished LINE, losing nothing. Zooming with the mouse wheel avoids this altogether, because the wheel zooms without starting a command and so never interrupts the one in progress. Zoom options are covered in our article on the ZOOM command.
Scripts and LISP often use command names prefixed with an underscore and a dot, such as _.LINE. Typed by hand, _.LINE runs exactly like LINE.
Selecting objects before the command: PICKFIRST
There are two working orders: start the command then select, or select first then start the command. The second only works when the PICKFIRST variable is 1.
PICKFIRST | Select one line first, then type ERASE |
|---|---|
| 1 | AutoCAD reports 1 found and erases the selected line at once |
| 0 | AutoCAD still asks Select objects: as if nothing were selected; the line survives |
Setting PICKFIRST to 0 on the 2027 release also prints a warning on the command line.
**** System Variable Changed ****
2 of the monitored system variables have changed from the preferred value. Use SYSVARMONITOR command to view changes.That is the system variable monitor: AutoCAD watches a set of important variables and warns when they move from their preferred values. Here the warning appeared right after PICKFIRST was set to 0. Type SYSVARMONITOR to see exactly which variables changed. If a command keeps asking you to select again, check PICKFIRST first. Other selection methods are covered in our article on selecting objects.
Reviewing what you typed
The command line keeps a history. The 2027 release remembers the last 20 inputs by default (CMDINPUTHISTORYMAX is 20). To read back everything AutoCAD printed, such as a measurement or an error that scrolled past, press Ctrl+F2. The acad.cuix file assigns this key to Text Window, which opens the full command-line text for the session.
The text window is especially useful for commands that print several lines, such as measuring distance with its two result lines. Read them there rather than scrolling a short command line.
A classic mistake: typing a point with no command running
Coordinates only mean something while a command is asking for a point. Type 0,500 at an empty Command: prompt and AutoCAD takes it as a command name:
Command: 0,500
Unknown command "0,500". Press F1 for help.This usually happens when a command ended one Enter earlier than you thought. Nothing is drawn and nothing is lost; start the command again and type the point.
How to enter commands in AutoCAD, by situation
| Situation | Do this |
|---|---|
| Starting a familiar command | Type its alias, then Enter or Space |
| Using the last command again | Enter at an empty Command: prompt |
| The prompt offers options in square brackets | Type the capital letters |
| Zooming halfway through a command | Mouse wheel, or 'ZOOM except options needing a regen |
| Objects already selected | Type the command, with PICKFIRST = 1 |
| Wrong turn, want out | Esc |
Command line missing in AutoCAD: why, and how to get it back
The command line is the "Type a command" box below the drawing area. It usually disappears for a simple reason: an accidental Ctrl+9. In the 2027 acad.cuix interface file, Ctrl+9 is assigned to Command Line, which toggles it. The Autodesk documentation states: "You can also press Ctrl+9 to toggle the display of the command window."
The two matching commands, with the state stored in CLISTATE:
| Command | Alias | Result |
|---|---|---|
COMMANDLINE | CLI | Shows the command line, CLISTATE = 1 |
COMMANDLINEHIDE | Asks for confirmation; Yes hides it, CLISTATE = 0 |
When hiding with COMMANDLINEHIDE, the 2027 release shows a "Command Line – Close Window" box with the way back already spelled out: "To display the Command Line window again, press CTRL+9." It also has an "Always close the Command Line window" box; as its name says, ticking it means closing without asking in future, so a stray Ctrl+9 later brings no reminder.
How to show the command line
| Route | What to do |
|---|---|
| Quickest | Press Ctrl+9 |
| Type a command | Type COMMANDLINE or CLI, Enter |
| Classic menu (with the menu bar on) | Tools → Command Line |
A common mistake is blaming Clean Screen, Ctrl+0. It hides the ribbon and palettes but leaves the command line alone: with Clean Screen on, CLEANSCREENSTATE becomes 1 while CLISTATE stays 1. If the command line is gone but the ribbon is still there, the culprit is Ctrl+9, not Ctrl+0.
Autodesk also notes: "When the Command Line is hidden, you can enter commands using dynamic input boxes, which are displayed near the cursor." With the command line hidden, the dynamic input box by the cursor is the only place prompts still appear. If dynamic input is off too (DYNMODE = 0), you no longer see what AutoCAD is asking at all, which is exactly when Ctrl+9 matters most.
Frequently asked questions
The command line is missing in AutoCAD. How do I get it back?
Press Ctrl+9, or type COMMANDLINE and Enter.
What is the alias for the COMMANDLINE command?
CLI.
Why does a command ask me to select again after I selected first?
PICKFIRST is 0. Set it to 1 and commands use the existing selection.
How do I repeat the last command?
Press Enter or Space at an empty Command: prompt. AutoCAD starts the last command again and shows its name, such as LINE, on the command line before the first prompt.
How do I choose an option in square brackets?
Type the capital letters of the option, such as 2P for a circle through two diameter ends, then Enter.
Why does 'ZOOM then E say cannot be transparent?
Zoom Extents needs a full regeneration, so it cannot run inside another command. AutoCAD returns to the previous command; zoom with the mouse wheel instead.