Is there a way to dump syntax highlighting to a .vim file?

Question

If I set syntax highlighting rules manually (not in a file), is there a way to save them out to a file? Specifically, the goal is to source this file to restore the syntax highlighting rules later on.

Answer 1

No, there is no command that will save the syntax/highlight definitions to a file that can be parsed to restore the same definitions at a later stage. Or, to be more specific, I do not think that any such command exists. I also do not know of any plugins or addons that will do this.

However, the command history is stored in ~/.viminfo. Thus, if you want to copy manually typed highlight/syntax commands into a file for later sourcing, you may copy the relevant commands from the command history. Of course, this requires some manual parsing and tweaking, but I think this is the simplest solution to your problem.

For more details, see:
- :h viminfo
- :h 'viminfo'

Answer 2

You can use :redir for that.

Dump highlight definitions:

:redir > file
:hi
:redir END

Dump syntax definitions:

:redir > file
:syntax
:redir END

Notes:

• you will probably need to press G and <CR> to get to the end of the listing if you don't want to go through everything.
• neither method will produce a working syntax script or a working colorscheme, you will need to edit the result anyway.

See :help :redir

Answer 3

This may be helpful for future readers:

This function returns an executable command which can restore the actual highlight attributes for one highlight group (not fully tested, but it handles linked groups):

function! GetHiCommand(group)
    redir => l:output
        silent! exec 'hi' a:group
    redir end

    let l:link = matchstr(l:output, 'links to \zs\w\+')

    if empty(l:link)
        let l:attrs = matchstr(l:output, '\<xxx \zs[^\n]*')
        return printf('hi %s %s', a:group, l:attrs)
    else
        return printf('hi! link %s %s', a:group, l:link)
    endif
endf

Example output:

:echo GetHiCommand('LineNr')
hi LineNr term=underline ctermfg=243 guifg=#7c6f64

:echo GetHiCommand('MoreMsg')
hi! link MoreMsg GruvboxYellowBold