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Erase to BOL (EL 1)
ESC [ 1 KEL 1 erases from the beginning of the line to the cursor position (inclusive). The sequence is
ESC [ 1 K. Less commonly used than EL 0 (erase to end of line).
EL 1 is the mirror image of the common EL 0 erase-to-end operation. It is useful for redrawing the left side of a prompt or clearing a partially typed command while preserving content to the right. Because the cursor does not move, applications can combine it with precise cursor addressing instead of repainting an entire row.How this is testedautomated
Write "XXXXX", move to col 3, send
Write "XXXXX", move to col 3, send
\x1b[1K (EL 1), verify cell at (0,0) is blank.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.
Analysis2026-05-17
Supported by all 12 tested terminals — universal adoption. Part of the Core TUI baseline.
Supported by 13 of 14 backends (93%)
Terminal Applications
| Terminal | Version | Support | Notes |
|---|---|---|---|
| iTerm2 | 3.6.9 | ✓ yes | |
| Ghostty | 1.3.1 | ✓ yes | |
| VS Code | ✓ yes | ||
| Warp | ✓ yes | ||
| Kitty | 0.46.2 | ✓ yes | |
| Cursor | ✓ yes | ||
| Terminal.app | ✓ yes |