Reverse wrap

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Experimental

Reverse Wrap (Mode 45) is a DECSET/DECRST mode that controls whether a backspace at the beginning of a line wraps the cursor to the end of the previous line.

Syntax

CSI ? 45 h    DECSET — Enable reverse wraparound
CSI ? 45 l    DECRST — Disable reverse wraparound

Formal syntax

DECSET-mode45 = 0x1b, "[", "?", "4", "5", "h" ;
DECRST-mode45 = 0x1b, "[", "?", "4", "5", "l" ;

Description

Mode 45 is an XTerm extension that enables reverse wraparound. When a backspace (BS, 0x08) is received while the cursor is at the first column, this mode controls whether the cursor wraps to the last column of the previous line.

• Set (reverse wrap on) — A backspace at column 1 moves the cursor to the last column of the previous line. If the cursor is at the top-left corner of the screen (or scrolling region), the backspace has no effect.
• Reset (reverse wrap off) — A backspace at column 1 has no effect; the cursor stays at column 1. This is the default.

Requirements

Reverse wrap only occurs when both of the following conditions are met:

1. Mode 45 (reverse wraparound) is enabled
2. DECAWM (Mode 7, auto-wrap) is also enabled

If auto-wrap is disabled, reverse wrap has no effect regardless of Mode 45.

Scope

Reverse wrap only applies to the BS (backspace) control character. Cursor movement sequences like CUB (CSI D) do not wrap regardless of this mode; they stop at column 1.

note

XTerm also supports Mode 1045, which is a variant that interacts differently with the alternate screen buffer. Mode 45 is the more commonly implemented variant.

Examples

printf '\e[?7h'      # Enable auto-wrap (required for reverse wrap)
printf '\e[?45h'     # Enable reverse wraparound
printf '\e[?45l'     # Disable reverse wraparound

Specifications

Specification	Section
XTerm ctlseqs	—

Terminal support

Terminal	Support	Version	Notes
Terminal Emulators
Alacritty	✗	No
Bobcat	✓	0.9.0	Implemented in TerminalCtrl library. Configurable via ReverseWrap setting.
contour	✗	No	Explicitly marked as TODO at primitives.h:879
foot	✓	Yes
Ghostty	✓	v1.0.0
iTerm2	✓	v20260216-nightly
Kitty	✗	No
Konsole	✗	No
mintty	✓	Yes	Implemented at src/termout.c:2425
mlterm	✗	No	Permanently reset (never enabled) according to get_vtmode()
PuTTY	✗	No
Rio	✗	No
rxvt-unicode	✗	No	Commented as 'margin bell NYI' in source
st	✗	No
terminology	✗	No	Marked as TODO at line 414 in termptyesc.c
VT100	✗	No
VTE	✓	Yes
WezTerm	✓	Yes
Windows Terminal	✗	No	No implementation found in codebase
xterm	✓	380	Original mode 45 implemented in patch 380, extended mode 1045 in patch 383
xterm.js	✓	4.6.0
Multiplexers
cy	✗	No
GNU Screen	✗	No
tmux	✗	No
tuios	✗	No
Zellij	✗	No

See also

• DECAWM — Auto-Wrap Mode — Required for reverse wrap to function
• BS — Backspace — The backspace control character affected by this mode