c:\test>p1
[0] Perl> system qq[tasklist /fi "PID eq $$"];;

Image Name                   PID Session Name     Session#    Mem Usage
========================= ====== ================ ======== ============
perl.exe                     888                         0      2,972 K
[0] Perl> open RAM, '>', \$ram;;
[Bad file descriptor] Perl> print RAM 'X' x 1e6 for 1 .. 100; print length $ram;;
100000100
[0] Perl> system qq[tasklist /fi "PID eq $$"];;

Image Name                   PID Session Name     Session#    Mem Usage
========================= ====== ================ ======== ============
perl.exe                     888                         0    101,008 K
[0] Perl> close RAM;;
[0] Perl> undef $ram;;
[0] Perl> system qq[tasklist /fi "PID eq $$"];;

Image Name                   PID Session Name     Session#    Mem Usage
========================= ====== ================ ======== ============
perl.exe                     888                         0      3,256 K