DB<1> b work
  DB<2> c
main::work(test.pl:12):         $pid = open PROC, 
main::work(test.pl:13):     'perl -le"$|=1; print and select(undef,undef,undef,0.1) for 1 .. 1000" |'
main::work(test.pl:14):                 or die $!;
  DB<2> n
  DB<2> x $pid
0  9940
  DB<3> x $$                                    
0  9850