--- File.chown(owner, group[, filename[, ...]])
--- File.lchown(owner, group[, filename[, ...]])     ruby 1.7 feature

    եΥʡȥ롼פѹޤѡ桼ե
    Υʡȥ롼פѹǤޤѹԤäեο
    ֤ޤѹ˼Ԥ㳰 Errno::EXXX ȯޤ

    owner  group ϡchown(2) [manual page] Ʊͤ
    ͤǻꤷޤ
    ѹ褦ʾ nil ޤ -1 ꤹ
    Ȥǥʡ䥰롼פ򸽺ߤΤޤޤˤ뤳ȤǤޤ

    lchown ϡܥå󥯤˴ؤƥ󥯤ΤΤΥʡ
    롼פѹޤlchown(2) [manual page] Ƥʤ
    ƥǤΥ᥽åɤƤӽФ NotImplementedError 㳰
    ȯޤ

