CSI CUU / CUD / CUF / CUB — Relative Cursor Moves

frame

CSI introducer: \x1b[ ESC [ (0x1B 0x5B)

terminator (none): ST · BEL

parameters / subcommands

gotchas

• A Pn of 0 is treated as 1, not as a no-op, per ECMA-48 default-parameter rules.
• These moves CLAMP at the screen edges and never scroll the buffer — to scroll, use SU/SD or move past the scroll region's bottom with newlines.
• CUF past the last column does not wrap to the next line; the cursor sticks at the right margin.
• Do not confuse CUD ('B') with index/newline: CUD never scrolls, whereas LF/IND can scroll at the bottom margin.
• 'CSI D' (CUB, back) is distinct from the C0 BS (0x08) backspace though both move left one cell.

provenance

• source: https://invisible-island.net/xterm/ctlseqs/ctlseqs.html
• version: xterm ctlseqs, patch #410, 2026/04/19
• retrieved: 2026-05-29 · updated: 2026-05-29T00:00:00Z

per-fact attribution:

• #summary — https://invisible-island.net/xterm/ctlseqs/ctlseqs.html xterm ctlseqs: CSI Ps A = Cursor Up Ps (CUU); CSI Ps B = Cursor Down (CUD); CSI Ps C = Cursor Forward (CUF); CSI Ps D = Cursor Backward (CUB). Default Ps = 1.
• ext.params — https://ecma-international.org/publications-and-standards/standards/ecma-48/ ECMA-48 defines CUU/CUD/CUF/CUB with a single Pn parameter defaulting to 1.

see also

• terminal-csi/cup
• terminal-csi/cnl
• terminal-csi/cha