ECH Erase Character
Blank n characters from the cursor rightwards, without moving anything.
CSI Pn X
- Defaults
- Pn = 1
- ECMA-48
- §8.3.38 ECH – Erase Character, p. 41
- DEC STD 070
- §5.11 Erase Character, p. 5-152
- VT220
- §4.12 Erasing
- VT510
- ECH—Erase Character
Erase the character under the cursor and the Pn − 1 after it. A 0 is taken as 1. Nothing else on the line moves, and neither does the cursor. Asking for more characters than are left on the line erases to the end of the line and stops; ECH never continues onto the next one.
Unlike DCH and ICH, ECH ignores the margins. DEC STD 070 says it “is not affected by the margins”, and the VT510 manual that it “works inside or outside the scrolling margins”. The erased cells lose their character attributes as well as their characters.
EL erases from the cursor to the end of the line in one go.
Support
| Terminal | Version | Support | Notes |
|---|---|---|---|
| VT220 | manual, 2nd ed., 1984 | Yes | §4.12 Erasing |
| VT510 | manual, 1st ed., 1993 | Yes | ECH |
| xterm | patch 412, xterm-411a | Yes | |
| libghostty-vt | 0f171f6 | Yes | |
| kitty | 0.49.1, run in a VM | Yes | passes the 5 cases that show it working |
| foot | 1.28.0, run in a VM | Yes | passes the 4 cases that show it working |
| pyte | 0.8.2, run as a library | Yes | passes the 5 cases that show it working |
| xterm.js headless | 6.0.0, run as a library | Yes | passes the 5 cases that show it working |
| alacritty_terminal | 0.26.0, run as a library | Yes | passes the 5 cases that show it working |
| ConEmu | build 230724, its documentation | Yes | ANSI escape codes |
| rxvt-unicode | 9.31, run in a VM | Yes | passes the 5 cases that show it working |
| VTE | 0.84.1, run as a library | Yes | passes the 4 cases that show it working |
Validation
ECH-1: Erase one character
ABCDE
\e[1;2H
\e[X
|A_CDE|
cursor 1,2
ECH-2: Erase three
ABCDE
\e[1;2H
\e[3X
|A___E|
ECH-3: Stops at the end of the line
ABCDE\r\nFGHIJ
\e[1;4H
\e[99X
|ABC__|
|FGHIJ|
cursor 1,4
ECH-4: Ignores the margins
abcdefg
\e[?69h # allow left and right margins
\e[2;4s # margins at columns 2 and 4
\e[1;3H
\e[4X # runs past the right margin
|ab____g|
ECH-5: Attributes are erased too
\e[1mABC\e[m
\e[1;2H
\e[X
|A_C__|
attr 1,1 bold
attr 1,2 plain
attr 1,3 bold