my @x;
system "ps aux | grep $$ | grep [p]erl";
$x[1_000_000] = "foo";
system "ps aux | grep $$ | grep [p]erl";
undef @x;
system "ps aux | grep $$ | grep [p]erl";
push @x, "$_" for(1..1_000_000);
system "ps aux | grep $$ | grep [p]erl";
undef @x;
system "ps aux | grep $$ | grep [p]erl";
------
oha       8305  0.0  0.2  3296 1232 pts/0    S+   19:55   0:00 perl t4.pl
oha       8305  0.0  0.9  7204 5148 pts/0    S+   19:55   0:00 perl t4.pl
oha       8305  0.0  0.2  3296 1244 pts/0    S+   19:55   0:00 perl t4.pl
oha       8305 76.0  8.6 46896 44800 pts/0   S+   19:55   0:00 perl t4.pl
oha       8305 98.0  7.8 42796 40704 pts/0   S+   19:55   0:00 perl t4.pl