perl -we'my $cmd = qq{top -b -n 1 |grep };
print "$$ start\n";print qx{$cmd $$};
my $s="";my $x = "_" x $ARGV[0];
print "string\n";print qx{$cmd $$};
if (my $pid = fork) {
  print "parent $$ forked $pid\n";print qx{$cmd $$};
  $s = "<".$s.">";
}
else {
  print "child $$\n";print qx{$cmd $$};
  $s = "(".$s.")";sleep 3; print "child slept 3\n";
}
print "$$ end\n";print qx{$cmd $$};' 100000000