Process::WNOHANG e$B$,8z$-$^$;$s!#e(B
e$B0J2<$r<B9T$9$k$H!"e(B3 e$BIC$[$IBT$C$F$7$^$$$^$9!#e(B
% ./ruby -ve ’
pid = fork { sleep 3 }
p Process.waitpid(pid, Process::WNOHANG)’
ruby 1.9.0 (2007-09-26 patchlevel 0) [i686-linux]
8662
WNOHANG e$B$r;XDj$7$F$"$k$N$GB(:B$Ke(B nil e$B$rJV$9$O$:$G!"e(B1.8
e$B$G$Oe(B
e$B$=$N$h$&$KF0$-$^$9!#e(B
% ruby-1.8 -ve ’
pid = fork { sleep 3 }
p Process.waitpid(pid, Process::WNOHANG)’
ruby 1.8.6 (2007-09-26 patchlevel 5000) [i686-linux]
nil