--- MAKEFILE_CONFIG
    CONFIG ƱǤͤϰʲΤ褦ʷ
    ¾ѿؤλȤޤߤޤ
        MAKEFILE_CONFIG["bindir"] = "$(exec_prefix)/bin"
    ϡMakefile ѿȤη MAKEFILE_CONFIG ϡ
    Makefile κݤѤ뤳ȤꤷƤޤ

        require 'rbconfig'

        print <<-END_OF_MAKEFILE
        prefix = #{Config::MAKEFILE_CONFIG['prefix']}
        exec_prefix = #{Config::MAKEFILE_CONFIG['exec_prefix']}
        bindir = #{Config::MAKEFILE_CONFIG['bindir']}
        END_OF_MAKEFILE

        => prefix = /usr/local
           exec_prefix = $(prefix)
           bindir = $(exec_prefix)/bin

    Config.expand ϡΤ褦ʻȤ褹
    ᥽åɤȤ rbconfig.rb ѤƤޤ
    (CONFIG ѿϡMAKEFILE_CONFIG Ƥ 
    Config.expand ȤäƤޤ)

        require 'rbconfig'
        p Config.expand(Config::MAKEFILE_CONFIG["bindir"])
        # => "/usr/local/bin"

