$ perl -MDevel::Peek -e'sub f { my $x; Dump($x); $x="abc"; } f;f;'
SV = NULL(0x0) at 0x93fcee0
  REFCNT = 1
  FLAGS = (PADMY)
SV = PV(0x93eb040) at 0x93fcee0
  REFCNT = 1
  FLAGS = (PADMY)
  PV = 0x93f8e00 "abc"\0
  CUR = 3
  LEN = 4