Colored and styled underlines
================================
|kitty| supports colored and styled (wavy) underlines. This is of particular use
in terminal based text editors such as :program:`vim` and :program:`emacs` to
display red, wavy underlines under mis-spelled words and/or syntax errors. This
is done by re-purposing some SGR escape codes that are not used in modern
terminals (`CSI codes <https://en.wikipedia.org/wiki/ANSI_escape_code#CSI_(Control_Sequence_Introducer)_sequences>`__)
To set the underline style::
<ESC>[4:0m # no underline
<ESC>[4:1m # straight underline
<ESC>[4:2m # double underline
<ESC>[4:3m # curly underline
<ESC>[4:4m # dotted underline
<ESC>[4:5m # dashed underline
<ESC>[4m # straight underline (for backwards compat)
<ESC>[24m # no underline (for backwards compat)
To set the underline color (this is reserved and as far as I can tell not
actually used for anything)::
<ESC>[58...m
This works exactly like the codes ``38, 48`` that are used to set foreground and
background color respectively.
To reset the underline color (also previously reserved and unused)::
<ESC>[59m
The underline color must remain the same under reverse video, if it has a color,
if not, it should follow the foreground color.
To detect support for this feature in a terminal emulator, query the terminfo
database for the ``Su`` boolean capability.
Generated by dwww version 1.15 on Wed May 22 22:37:49 CEST 2024.