get_local_prefix Function

    function get_local_prefix(os) result(prefix)
        !> Installation prefix
        character(len=:), allocatable :: prefix
        !> Platform identifier
        integer, intent(in), optional :: os

        !> Default installation prefix on Unix platforms
        character(len=*), parameter :: default_prefix_unix = "/usr/local"
        !> Default installation prefix on Windows platforms
        character(len=*), parameter :: default_prefix_win = "C:\"

        character(len=:), allocatable :: home

        if (os_is_unix(os)) then
            home=get_env('HOME','')
            if (home /= '' ) then
                prefix = join_path(home, ".local")
            else
                prefix = default_prefix_unix
            end if
        else
            home=get_env('APPDATA','')
            if (home /= '' ) then
                prefix = join_path(home, "local")
            else
                prefix = default_prefix_win
            end if
        end if

    end function get_local_prefix