/\x40\z/ =~ "\x81\x40".force_encoding("GBK")

GBK e$B$G$Oe(B \x81\x40 e$B$OC10l$NJ8;z$@$H;W$&$N$G$9$,!"0J2<$N$h$&$Ke(B
e$B$9$k$H8e$mH>J,$Ne(B \x40 e$B$K%^%C%A$7$^$9!#e(B

% ./ruby -ve ‘p(/\x40\z/ =~ “\x81\x40”.force_encoding(“GBK”))’
ruby 1.9.0 (2008-01-29 revision 15312) [i686-linux]
0

\z e$B$r$D$1$J$1$l$P%^%C%A$7$^$;$s!#e(B

% ./ruby -ve ‘p(/\x40/ =~ “\x81\x40”.force_encoding(“GBK”))’
ruby 1.9.0 (2008-01-29 revision 15312) [i686-linux]
nil

e$B@.@%$G$9!#e(B

Tanaka A. wrote:

ruby 1.9.0 (2008-01-29 revision 15312) [i686-linux]
nil

r15321 e$B$GD>$;$?$H;W$$$^$9!#e(B