Cursor shape support

[dabeibao]

The escape sequence is:
ESC[N q

N is between 0 and 6.

[achernya]

What is the context of this?

[dabeibao]

Please see the link:
https://gist.github.com/fnky/458719343aabd01cfb17a3a4f7296797?permalink_comment_id=5165100#gistcomment-5165100

Many modern terminals (including Windows Terminal, mintty, etc.) support changing the cursor shape dynamically — and this pairs beautifully with Emacs Evil mode, so you can visually distinguish between Normal and Insert modes (like in Vim).

Normal mode:

Insert mode:

[achernya]

Is there any more authoritative documentation of these escape sequences?

[dabeibao]

What about this: https://invisible-island.net/xterm/ctlseqs/ctlseqs.html

Search 'CSI Ps SP q' in the page:

CSI Ps SP q
          Set cursor style (DECSCUSR), VT520.
            Ps = 0  ⇒  blinking block.
            Ps = 1  ⇒  blinking block (default).
            Ps = 2  ⇒  steady block.
            Ps = 3  ⇒  blinking underline.
            Ps = 4  ⇒  steady underline.
            Ps = 5  ⇒  blinking bar, xterm.
            Ps = 6  ⇒  steady bar, xterm.

[achimnol]

We have long standing PRs and issues for this feature.

• Cursor Color and Style changes #352 (duplicate: Cursor style not handled correctly #1084)
• Apply Clang formatting to #1167 and resolve merge conflicts #1292
• Closed in favor of #1292 #1167

[eminence]

I'm looking at the impl for Dispather::getparam and it looks like doesn't support returning values less than 1. But 0 is a valid cursor shape.

[dabeibao]

Thanks. The defaultval should be 0.

[dabeibao]

* [Apply Clang formatting to #1167 and resolve merge conflicts #1292](https://github.com/mobile-shell/mosh/pull/1292)

Seems this commit already implements it. But the title is somewhat misleading...

[eminence]

Something's still not quite right when the terminal is reset. Try this:

printf '\x1b[6 q\x1bc'