How to shorten the branch name to 40 characters if not enough space?

[alexventuraio]

The branch name is taking most of the space available within the split and even the filename is not being shown. I would prefer to shorten the branch name to the last 40 characters only and have the file name visible, is there a way to achieve that?

This is my current config

lualine.setup({
  options = {
    icons_enabled = true,
    theme = 'powerline',
    disabled_filetypes = { 'NvimTree' },
    component_separators = { left = '', right = '' },
    section_separators = { left = '', right = '' },
  },
  sections = {
    lualine_b = {
      'branch',
      {
        'diff',
        colored = true, -- Displays a colored diff status if set to true
        diff_color = {
          -- Same color values as the general color option can be used here.
          added    = 'DiffAdd',    -- Changes the diff's added color
          modified = 'DiffChange', -- Changes the diff's modified color
          removed  = 'DiffDelete', -- Changes the diff's removed color you
        },
      },
      'diagnostics'
    },
    lualine_c = {
      {
        'filename',
        file_status = true,      -- Displays file status (readonly status, modified status)
        newfile_status = true,   -- Display new file status (new file means no write after created)
        full_path = true,        -- 1: Relative path
        path = 1,
      }
    },
  },
  inactive_sections = {
    lualine_c = {
      {
        'filename',
        file_status = true,      -- Displays file status (readonly status, modified status)
        newfile_status = true,   -- Display new file status (new file means no write after created)
        full_path = true,        -- 1: Relative path
        path = 1,
      }
    },
  },
})

[yutkat]

local function get_branch()
	require("lualine.components.branch.git_branch").init()
	local branch = require("lualine.components.branch.git_branch").get_branch()
	return string.sub(branch, 1, 40)
end

  lualine_b = {
      get_branch,
      {
        'diff',
        colored = true, -- Displays a colored diff status if set to true
        diff_color = {
          -- Same color values as the general color option can be used here.
          added    = 'DiffAdd',    -- Changes the diff's added color
          modified = 'DiffChange', -- Changes the diff's modified color
          removed  = 'DiffDelete', -- Changes the diff's removed color you
        },
      },
      'diagnostics'
    },

[alexventuraio]

Thanks it worked too! ❤️

[fitrh]

You can use the fmt component options

{
    "branch",
    fmt = function(str)
        if vim.api.nvim_strwidth(str) > 40 then
            return ("%s…"):format(str:sub(1, 39))
        end

        return str
    end,
}

[alexventuraio]

Thanks it worked!
And how do I get the last 40 chars of the branch name instead of the first 40?

[fitrh]

You can try something like this

local strw = vim.api.nvim_strwidth(str)
if strw > 40 then
     return ("…%s"):format(str:sub(strw - 41, strw))
end