Multiple cursors

The terminal has one real cursor. bi puts it on the primary selection and draws the others as grey cells. The footer shows how many there are, because the mode label alone cannot tell you.

Ctrl-N: the next occurrence

lstring.c Rename with Ctrl-N 1 / 6 play

1. start The cursor is on nsize, the parameter of luaS_resize.
2. 1 Ctrl-N Ctrl-N adds a second cursor on the next nsize.
3. 2 Ctrl-NCtrl-N Twice more. Extra cursors are grey cells; the footer counts them.
4. 3 Ctrl-X Ctrl-X skips the match you do not want: the newest cursor leaves line 101 for 103.
5. 4 ciwnew_size Any edit now runs at every cursor — ciw then type.
6. 5 Esc Esc leaves insert mode; Esc again collapses back to one cursor. One u undoes the whole rename.

Ctrl-X is the same search as Ctrl-N with the opposite outcome: instead of leaving a cursor behind, it moves the one you just placed. So Ctrl-N Ctrl-X Ctrl-N takes the first and third occurrences and leaves the second alone.

Once the cursors are placed, everything applies at each one: motions, operators, text objects, insert, and .. One u undoes the edit, and the cursors come back with it.

A cursor per line

Ctrl-Alt-Down stacks cursors in a column. Use it when the lines have the same shape but no shared word.

lstring.c A cursor on every line 1 / 4 play

1. start The cursor is on the opening quote of "ldebug.h".
2. 1 Ctrl-Alt-Down×5 Ctrl-Alt-Down adds a cursor on the line below, in the same column.
3. 2 alua/ a then type: the text goes in at every cursor.
4. 3 EscEsc Esc leaves insert mode. A second Esc goes back to one cursor.

In visual mode: the selection

In visual mode Ctrl-N searches for the selection, not the word under the cursor. viw, Ctrl-N Ctrl-N, c is a rename of three occurrences.

lstring.c viw, Ctrl-N, c: a rename 1 / 5 play

1. start The cursor is on newvect.
2. 1 viw viw selects the word.
3. 2 Ctrl-NCtrl-N In visual mode Ctrl-N selects the next match of the selection. Pressed twice, three are selected.
4. 3 cvec c changes every selection at once.
5. 4 EscEsc Esc, Esc: back to one cursor. One u undoes the whole rename.

Blockwise visual

Ctrl-V selects a rectangle. Motions move one corner and the block follows, so Ctrl-V 3j 5l is four rows by six columns.

c, I and A leave a real cursor on every row, so the text appears on every row as you type.

linit.c Blockwise: $A on ragged rows 1 / 4 play

1. start Ten rows of luaL_Reg entries, each a different length.
2. 1 Ctrl-V9j$ Ctrl-V starts a block and 9j extends it down. $ makes every row reach its own line end.
3. 2 A /* std */ A puts a cursor at the end of every row, so the text appears on all of them while you type.
4. 3 EscEsc Esc, Esc. The whole thing is one undo step.

Rows too short to reach the block are skipped, except by A, which pads them with spaces so the appended text lines up. A yanked block is one register entry and pastes back as a rectangle.

:'v: commands over the selection’s shape

Pressing : with a selection prefills 'v, which means the selection itself, whatever shape it has. A command that rewrites text (:case, :s, :sort) then acts on exactly those characters: the columns of a rectangle, not the whole rows.

linit.c :'v acts on the rectangle 1 / 4 play

1. start The cursor is on the L of LUA_GNAME.
2. 1 Ctrl-V9j3l A block over the LUA_ column, ten rows tall.
3. 2 : : fills in 'v, which means the selection itself, whatever its shape.
4. 3 case lowerEnter case lower rewrites only the columns inside the block. The rest of each row is unchanged.

'<,'> still works and still means the rows. The 'v prefill is there so you can see which of the two you are running.