fish shell 起動時にアップデート可能なパッケージ数を表示

fish_greeting.fish

function fish_greeting -d "What's up, fish?"
    set_color $fish_color_autosuggestion

    set new_packages (command checkupdates)
    set new_packages_count (count $new_packages)

    if [ $new_packages_count -gt 0 ]
        if command echo $new_packages | command grep -q "\slinux\s[0-9]";
            command echo (count $new_packages) packages can be upgraded. These packages require restarting system.
        else
            command echo (count $new_packages) packages can be upgraded.
        end
    end

    set_color normal
end