blinking cursor with fish_vi_cursor in iTerm2

[nhooyr]

• Have you checked if problem occurs with fish 2.4.0?
• Tried fish without third-party customizations (check sh -c 'env HOME=$(mktemp -d) fish')?

fish version installed (fish --version): 2.4.0

OS/terminal used: iTerm2 3.0.13

In #3696, I mentioned that the cursor does not blink in insert mode with fish_vi_cursor.

@faho was unable to find the documentation on blinking for iTerm2. Neovim handles this fine, so perhaps @justinmk knows.

[krader1961]

iTerm2 supports the DECSCUSR command: CSI, Ps, space, "q". It implements two extensions: Ps=5 sets a blinking vertical bar, Ps=6 sets a non-blinking vertical bar. In the iTerm2 source look for VT100CSI_DECSCUSR in sources/VT100Terminal.m.

Fish implements a subset of these options in __fish_cursor_xterm. It looks like xterm supports the blinking variants according to this document and some other references I found.

[krader1961]

Also, FWIW, I think these functions should be named based on the capability implemented rather than a terminal that happens to support the capability; e.g., __fish_cursor_decscusr rather than __fish_cursor_xterm.

[faho]

I think these functions should be named based on the capability implemented rather than a terminal that happens to support the capability

__fish_cursor_xterm is the version for xterm, while __fish_cursor_konsole is the one for konsole and __fish_cursor_1337 is for newer iTerm (the only difference to konsole is that the number is 1337 instead of 50).

All of them handle the same capability, but in different terminals.

It looks like xterm supports the blinking variants according to this document and some other references I found.

For xterm, this is already implemented.

It implements two extensions: Ps=5 sets a blinking vertical bar, Ps=6 sets a non-blinking vertical bar

Good to know. So there's no blinking block or underscore?

[krader1961]

So there's no blinking block or underscore?

It does, same as iTerm2. It's just that a real VT520 doesn't support vertical bar; hence no Ps 5 or 6. Per the documents I linked to:

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).

[faho]

So the change needed here should be simple: Use __fish_cursor_xterm on iTerm as well. That leaves only konsole as the odd one out, but I can't find any way to set a blinking cursor there.

[christhekeele]

My iTerm2 reports as xterm-256color, so to work around instead of putting fish_vi_cursor in my config I did:

fish_vi_cursor and if string match -i -r xterm $TERM and __fish_cursor_xterm

[devsnek]

was this ever fixed? fish still overrides vertical bar in vi mode for me

[ridiculousfish]

@devsnek It sounds like you don't want fish's vi mode to adjust the cursor shape. Does no-oping fish_vi_cursor (e.g. function fish_vi_cursor ; end) solve this for you?

[devsnek]

@ridiculousfish yes, thanks