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| author | Nicolas Pitre <npitre@baylibre.com> | 2026-02-02 23:52:46 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-03-12 15:07:51 +0100 |
| commit | 4af70f151671da6acd7a1d7bae1469c576673d2d (patch) | |
| tree | 4cb2e834bfc2032df2c66720ed2809db16098165 | |
| parent | 24728b93fafe0949b5353e1a7b3a94175fe26d6e (diff) | |
| download | lwn-4af70f151671da6acd7a1d7bae1469c576673d2d.tar.gz lwn-4af70f151671da6acd7a1d7bae1469c576673d2d.zip | |
vt: add modifier support to cursor keys
Generate xterm-style CSI sequences with modifier parameters for arrow
keys when Shift, Alt, or Ctrl are held. For example, Shift+Up produces
ESC [ 1 ; 2 A instead of plain ESC [ A.
The modifier encoding follows the standard xterm convention:
mod = 1 + (shift ? 1 : 0) + (alt ? 2 : 0) + (ctrl ? 4 : 0)
When no modifiers are pressed, the original behavior is preserved.
Explicit keymap bindings for modified cursor keys (e.g., "shift keycode
103 = Find") take precedence over this automatic modifier encoding.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://patch.msgid.link/20260203045457.1049793-2-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/vt/keyboard.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/drivers/tty/vt/keyboard.c b/drivers/tty/vt/keyboard.c index 13bc048f45e8..cb907a3b9d3d 100644 --- a/drivers/tty/vt/keyboard.c +++ b/drivers/tty/vt/keyboard.c @@ -765,14 +765,39 @@ static void k_fn(struct vc_data *vc, unsigned char value, char up_flag) pr_err("k_fn called with value=%d\n", value); } +/* + * Compute xterm-style modifier parameter for CSI sequences. + * Returns 1 + (shift ? 1 : 0) + (alt ? 2 : 0) + (ctrl ? 4 : 0) + */ +static int csi_modifier_param(void) +{ + int mod = 1; + + if (shift_state & (BIT(KG_SHIFT) | BIT(KG_SHIFTL) | BIT(KG_SHIFTR))) + mod += 1; + if (shift_state & (BIT(KG_ALT) | BIT(KG_ALTGR))) + mod += 2; + if (shift_state & (BIT(KG_CTRL) | BIT(KG_CTRLL) | BIT(KG_CTRLR))) + mod += 4; + return mod; +} + static void k_cur(struct vc_data *vc, unsigned char value, char up_flag) { static const char cur_chars[] = "BDCA"; + int mod; if (up_flag) return; - applkey(vc, cur_chars[value], vc_kbd_mode(kbd, VC_CKMODE)); + mod = csi_modifier_param(); + if (mod > 1) { + char buf[] = { 0x1b, '[', '1', ';', '0' + mod, cur_chars[value], 0x00 }; + + puts_queue(vc, buf); + } else { + applkey(vc, cur_chars[value], vc_kbd_mode(kbd, VC_CKMODE)); + } } static void k_pad(struct vc_data *vc, unsigned char value, char up_flag) |