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DECIC — insert columns (CSI Ps ' })
CSI Ps ' }DECIC (DEC Insert Column) inserts N blank columns at the cursor's column position, shifting all content to the right of the cursor further right. The sequence is
ESC [ Ps ' } — note the apostrophe (intermediate) before }. Default Ps=1.
Columns shifted past the right margin are discarded. DECIC is the horizontal/column counterpart of IL (Insert Lines): IL inserts blank rows by shifting content down, DECIC inserts blank columns by shifting content right. It only operates on cells within the current scroll region (top/bottom margins) and the current left/right margin region if DECLRMM (mode 69) is enabled. Originally a VT420 feature, supported by xterm and some other modern terminals but not universally implemented.How this is testedautomated
Write content on multiple rows, position cursor in the middle, send
Write content on multiple rows, position cursor in the middle, send
\x1b[2'} (DECIC 2), verify the sequence is consumed without leaving literal characters on screen. Most headless backends don't implement column inserts, so verification is partial.The same probe runs against headless backends (via Termless) and real terminal apps (via a daemon launched in each terminal). This lets us distinguish parser correctness from rendering correctness.
Analysis2026-04-06
Supported by all 9 tested terminals — universal adoption. Part of the Rich TUI baseline.
Supported by 8 of 14 backends (57%)
Terminal Applications
| Terminal | Version | Support | Notes |
|---|---|---|---|
| iTerm2 | 3.6.9 | ✓ yes | sequence consumed |
| Ghostty | 1.3.1 | ✓ yes | sequence consumed |
| VS Code | ✓ yes | ||
| Warp | ✓ yes | ||
| Cursor | ✓ yes | ||
| Terminal.app | ✓ yes |
Headless Backends
Parser correctness only — a ✓ means the parser accepts the sequence.
| Backend | Version | Support | Notes |
|---|---|---|---|
| Alacritty | 0.26.0 | ✗ no | Column editing (SL/SR/DECIC/DECDC) not implemented — rarely needed by modern TUI apps |
| Kitty | 0.40.0 | ✗ no | Column editing (SL/SR/DECIC/DECDC) not implemented — rarely needed by modern TUI apps |
| vt100.js | 0.2.1 | ✗ no | Column editing (SL/SR/DECIC/DECDC) not implemented — rarely needed by modern TUI apps |
| vterm | 0.2.0 | ✗ no | Column editing (SL/SR/DECIC/DECDC) not implemented — rarely needed by modern TUI apps |
| WezTerm | 0.1.0-fork.5 | ✗ no | Column editing (SL/SR/DECIC/DECDC) not implemented — rarely needed by modern TUI apps |
| xterm.js | 5.5.0 | ✗ no | Column editing (SL/SR/DECIC/DECDC) not implemented — rarely needed by modern TUI apps |