DECSLRM — Set left and right margins (CSI Pl ; Pr s)

Constrain horizontal cursor movement + scrolling to columns Pl…Pr — the horizontal counterpart of DECSTBM.

Byte forms

Every common string-literal form so you can paste-and-search either direction.

\\x1b[\x1b[<Pl>;<Pr>s

\\033[\033[1;80s

\\e[\e[1;80s

ESC [ESC [ Pl ; Pr s

hex1b 5b ... 73

Description

Set Left and Right Margins. Defines a vertical strip — columns `Pl` (leftmost) through `Pr` (rightmost), 1-based, inclusive — within which cursor movement and scrolling are confined. Requires DECLRMM (left-right margin mode, `\x1b[?69h`) to be enabled first; without DECLRMM the sequence is silently ignored, and the final byte `s` instead means SCO save-cursor (this is the parse ambiguity that bites: `\x1b[s` with no params = save cursor, `\x1b[<Pl>;<Pr>s` with 2 params = DECSLRM if DECLRMM=on). Once active, SL/SR scrolling stays inside the strip, CUF/CUB clamp at the boundaries, and writes that hit the right margin wrap to the next row's left margin (instead of column 1). Paired with DECSTBM (`\x1b[<Pt>;<Pb>r`) the two margins define a rectangular scrolling region — the foundation for split-pane editors like vim's `:vsplit` rendering its left half independently of the right. Defaults if omitted: `Pl=1`, `Pr=` last column. Setting `Pl≥Pr` resets to the full screen width.

Spec citation: DEC STD 070 (DECSLRM) / DEC VT510 RM

Parameters

Pl	Leftmost column (1-based, inclusive). Default 1.
Pr	Rightmost column (1-based, inclusive). Default = screen width.

Examples

bash

printf '\033[?69h'        # enable DECLRMM first\nprintf '\033[10;30s'      # constrain cols 10..30\n# now scrolling + cursor moves stay within that strip

python

import sys\nsys.stdout.write('\x1b[?69h')          # enable DECLRMM\nsys.stdout.write('\x1b[1;40s')          # left margin 1, right 40

fmt.Print("\x1b[?69h\x1b[1;40s")    // enable + set strip

javascript

process.stdout.write('\x1b[?69h\x1b[1;40s')

printf("\x1b[?69h\x1b[1;40s");    /* enable DECLRMM + constrain to cols 1..40 */

Terminal support

xterm: yes
Linux console (fbcon): no
macOS Terminal.app: no
iTerm2: partial
Windows Terminal: no
cmd.exe / ConPTY: no
kitty: yes
alacritty: no
WezTerm: yes
Ghostty: partial
GNOME Terminal: no
Konsole: yes
tmux: no
GNU screen: no

xterm	Linux console (fbcon)	macOS Terminal.app	iTerm2	Windows Terminal	cmd.exe / ConPTY	kitty	alacritty	WezTerm	Ghostty	GNOME Terminal	Konsole	tmux	GNU screen
yes	no	no	partial	no	no	yes	no	yes	partial	no	yes	no	no

Related sequences

In the family cookbook

CSI cookbook · 5. Margins & scroll region — DECSTBM `r` and DECSLRM `s`