Command reference

How the command line works#

Every printable keystroke on the canvas is captured into the command line, where it is matched against command names and aliases. That single input path is what lets L, LINE, 10,5, @10<45 and a keyword letter all be typed the same way.

Prompts and keywords. A command asks in the form Specify next point or [Arc/Close/Undo]. A keyword is invoked by typing its capitalized letter or letters. A value in angle brackets is the default and Enter accepts it.

Autocomplete. Typing matches command names and aliases as you go, fuzzily — so every command's full canonical name is reachable even where the two-letter alias is the default.

History. F2 opens the expanded history window. The command line keeps a scrollback of prompts, answers and results.

Auto-repeat. Pressing Enter or Space at an idle prompt repeats the last command.

Transparency. PAN and ZOOM run inside another command without cancelling it. A half-drawn line still rubber-bands after a pan, and its cursor position is correct against the new view.

Order. Both noun-verb (select, then command) and verb-noun (command, then select) work everywhere.

Function keys#

Mouse#

Draw aliases#

Modify aliases#

Structure, annotation and view aliases#

Aliases are shipped defaults and are fully remappable. The classic two-letter codes are the defaults because someone who prefers full command names loses only a keystroke — autocomplete reaches every canonical name — while the drafter who loses CO loses their hands.

Draw commands#

LINE#

Creates independent segments, not a polyline. Each segment is a separate entity with its own id even though it shares vertex coordinates with its neighbours.

• Undo (U) removes the last committed segment and rewinds the start point, without exiting.
• Close (C) draws a final segment back to the first point and ends.
• Enter, Space or Esc ends the command; everything drawn so far is kept.

PLINE#

A single continuous entity of line and arc segments — an ordered vertex list where each vertex carries a bulge factor defining the curvature of the segment following it, plus a closed flag.

• Arc (A) switches subsequent segments to arcs, previewed tangent to the previous segment's exit direction. Line (L) switches back.
• Close (C) sets closed and draws the final segment.
• Undo (U) removes the last vertex.
• A polyline may carry a global width — a world-space width that scales with zoom, distinct from lineweight, which is screen-space.

CIRCLE, ARC, RECTANG, ELLIPSE, POLYGON#

CIRCLE defaults to Center-Radius, with Diameter, 2-Point, 3-Point and Tangent-Tangent-Radius as keywords. ARC offers the standard construction variants. RECTANG takes two opposite corners with Chamfer, Fillet, Width and Rotation keywords. ELLIPSE is a rotatable centre-and-two-axes entity. POLYGON takes a side count and an inscribed or circumscribed radius.

POINT, DIVIDE, MEASURE#

POINT places node entities, drawn using a named point style (dot, cross, x, circle-cross, square) rather than a numeric code. DIVIDE places N points evenly along an entity; MEASURE places one every D units. Both can place a block instead of a point.

SPLINE, XLINE, RAY#

SPLINE fits a smooth curve through or near control points. XLINE draws an infinite construction line; RAY draws one that is infinite in one direction.

Modify commands#

ERASE#

With a selection active, Delete erases immediately. Run as a command, ERASE prompts for a selection, greys the pending entities, and commits on Enter or Space — Esc restores them. Entities on locked layers are ignored entirely, and everything erased is fully recoverable by undo.

OOPS restores the most recently erased set while keeping the work done since. That is the case it is always reached for, and it is why undo does not cover it: undo would roll back everything after the erase.

MOVE and COPY#

Both flow selection → base point → displacement, with a ghost preview tracking the cursor. COPY additionally:

• loops — the base point stays fixed and each click drops another copy;
• Displacement (D) takes a raw delta such as 10,5, makes one copy and ends;
• Array (A) takes a count and a second point, placing N copies evenly along that vector.

Copies are fully independent: new ids, no shared references to the source.

ROTATE and SCALE#

Selection → base point → angle or factor, with a live ghost. Both offer:

• Copy (C) — keep the originals and transform a clone.
• Reference (R) — for ROTATE, pick two points to define the current angle then specify the desired one; for SCALE, give a current length and a desired length.

SCALE is uniform only: X and Y factors are always equal. A factor of 0 is rejected with a user-facing error.

MIRROR#

Selection → two axis points (with a live reflected ghost) → Erase source objects? [Yes/No] <No>.

Text stays readable. Text, dimensions and attributes are repositioned by the reflection but remain left-to-right; glyphs are never reversed. Literal glyph mirroring is available as a Reverse text (R) keyword for the rare case that wants it. Arc sweep direction inverts under reflection.

STRETCH#

Deforms geometry rather than moving it: vertices inside the crossing window move, vertices outside stay put, and the spans between them stretch.

OFFSET#

1. Specify an offset distance, or choose Through.
2. Pick the source entity.
3. Click the side. A parallel copy is generated at that distance on that side.
4. The command loops, keeping the same distance.

Lines offset along their perpendicular normal; circles and arcs by changing radius; polylines segment-by-segment with corners rebuilt from the new intersections. In Through mode there is no distance up front — the preview tracks the cursor and the click fixes the geometry.

Two edge cases are handled deliberately rather than left to produce broken geometry. Collapse: offsetting a circle inward past its radius, or a polyline inward until segments cross or vanish, either rejects the operation or discards the collapsed segments. Mitre capping: on the convex side of a sharp corner the offset spans diverge, so a 10° V offset by 1 would mitre to a point 11.5 away pointing back past its own vertex — past four times the offset distance the corner is bevelled instead.

TRIM and EXTEND#

Every visible entity is an implicit cutting edge. Click a segment and it trims to its nearest intersections; there is no separate boundary-selection step.

• Click-side resolution: the exact click coordinate decides which portion is removed — the piece between the two intersections bracketing the click.
• Splitting: trimming the middle of an entity replaces it with two entities, both inheriting the original's layer, colour, linetype and lineweight.
• Fence: draw a temporary fence line and every object it crosses is trimmed, once each, at the first crossing along the fence. Crossings are resolved before any trimming, so the same gesture does the same thing from either end.

FILLET and CHAMFER#

Round or bevel the corner between two entities. Both take a radius or distance first, then two picks, and both offer a Polyline (P) mode that applies the operation to every corner of a polyline at once. A radius or distance of 0 trims or extends the two entities to a sharp corner.

ARRAY#

Three types, all associative — the array is a live parametric entity, not a one-off copy.

• Rectangular: columns, rows, levels, and the spacing between each.
• Polar: centre point, item count, angle to fill, and whether items rotate as they are copied.
• Path: distributes along a line, polyline, arc or spline. Divide places N items evenly along the total length; Measure places one every D units. Items optionally align to the path tangent.

Editing a parameter regenerates immediately. A source edit state lets you modify the base geometry and have every instance follow, and individual items can be repositioned or deleted without exploding the array.

BREAK, JOIN and LENGTHEN#

BREAK removes the span between two picked points, taken in either order. JOIN merges collinear or contiguous entities into one, including joining spans into a polyline. LENGTHEN changes an entity's length by delta, percent, total length or dynamically.

MATCHPROP#

Pick a source entity, then pick destinations to copy its properties onto — layer, colour, linetype, lineweight, and style properties for text and dimensions.

Inquiry — DIST, AREA, LIST#

DI reports distance and angle between two points. AA reports area and perimeter, with Add and Subtract modes for composite regions. LI lists everything the drawing knows about the selected entities.