use strict;
use warnings;
use Thread;
use Time::HiRes qw(usleep);

my $count = 0;
print "          VIRT    RES   SHR  S %CPU %MEM  TIME+\n";
while( 1 ) {
    usleep(100);
    my $thr1 = new Thread \&doNothing;
    $thr1->join;
    unless( ++$count % 1000 ) {
      printf "%-10s%4s  %3s  %3s  %s %4s %4s  %s\n"
        , "$count: "
        , map { s/^\s+//; (split(/\s+/,$_,-1))[4..10]
              } grep {/^\s*$$/} qx{top -n 1 -p $$ -b};
    }
}

sub doNothing {}
__END__
          VIRT    RES   SHR  S %CPU %MEM  TIME+
1000:     13536  3784  1488  S  0.0  1.5  0:01.03
2000:     14256  4504  1492  S  0.0  1.8  0:11.59
3000:     14980  5220  1492  S  0.0  2.0  0:12.27
4000:     15700  5936  1492  S  0.0  2.3  0:20.39
5000:     16420  6652  1492  S  0.0  2.6  0:30.56
6000:     17144  7368  1492  S  0.0  2.9  0:40.29
7000:     17864  8084  1492  S  0.0  3.2  0:41.38
8000:     18504  8800  1492  S  0.0  3.4  0:42.78
9000:     19224  9516  1492  S  0.0  3.7  0:46.31
10000:    19944   9m  1492  S  0.0  4.0  0:50.17
11000:    20664  10m  1492  S  0.0  4.3  0:52.94
12000:    21388  11m  1492  S  0.0  4.5  0:53.33
13000:    22108  12m  1492  S  0.0  4.8  0:54.48
14000:    22828  12m  1492  S  0.0  5.1  1:00.93
15000:    23552  13m  1492  S  0.0  5.4  1:13.55
16000:    24272  14m  1492  S  0.0  5.7  1:23.45
17000:    24992  14m  1492  S  0.0  5.9  1:30.25
18000:    25712  15m  1492  S  0.0  6.2  1:30.35
19000:    26432  16m  1492  S  0.0  6.5  1:38.96
20000:    27152  16m  1492  S  0.0  6.8  1:49.57
21000:    27872  17m  1492  S  0.0  7.1  1:59.23
22000:    28592  18m  1492  S  2.0  7.3  1:59.82
23000:    29312  19m  1492  S  0.0  7.6  2:02.34
24000:    29956  19m  1492  S  0.0  7.9  2:09.54
25000:    30676  20m  1492  S  0.0  8.2  2:18.27
26000:    31396  21m  1492  S  0.0  8.5  2:21.90
27000:    32116  21m  1492  S  0.0  8.7  2:30.96
28000:    32836  22m  1492  S  0.0  9.0  2:33.76
29000:    33556  23m  1492  S  0.0  9.3  2:34.37
30000:    34276  23m  1492  S  0.0  9.6  2:37.70
31000:    34996  24m  1492  S  2.0  9.9  2:46.51
32000:    35716  25m  1492  S  0.0 10.1  2:56.34
33000:    36436  26m  1492  S  0.0 10.4  3:06.34
34000:    37156  26m  1492  S  0.0 10.7  3:14.56
35000:    37876  27m  1492  S  0.0 11.0  3:22.40
...
163000:   126m  116m  1492  S  2.0 46.7  16:06.57
164000:   127m  117m  1492  S  0.0 47.0  16:08.22