Ķѿɽ֥ȡHash ƱͤΥ󥿡ե
ޤHash ȰۤʤꡢENV Υͤˤʸ󤷤
Ȥ뤳ȤǤޤ

ENV ʸ ENV['PATH'] ƱƤ
(֥Ȥα˴ؤƤϥƥǥ򻲾ȤΤ)
ENV['PATH'] ϤǤïǤ񤭹߲ǽʥǥ쥯ȥޤ
Ǥ˸¤ޤ

        p ENV['TERM'].tainted?
        # => true
        p path = ENV['PATH']
        # => "/usr/local/bin:/usr/bin:/bin:/usr/X11/bin"
        p path.tainted?
        # => false

ruby 1.8 feature:
ޤENV ʸ freeze Ƥޤ

        p ENV['TERM'].frozen?
        # => true