> perl -T -E'use Devel::Peek; my ($foo) = @ARGV; Dump $foo; my ($u) = $foo =~ /(b)/; Dump $u' blah
SV = PVMG(0x8be4b0) at 0x8c3098
  REFCNT = 1
  FLAGS = (PADMY,GMG,SMG,pPOK)
  IV = 0
  NV = 0
  PV = 0x8a65d0 "blah"\0
  CUR = 4
  LEN = 8
  MAGIC = 0x8c6b40
    MG_VIRTUAL = &PL_vtbl_taint
    MG_TYPE = PERL_MAGIC_taint(t)
    MG_LEN = 1
SV = PV(0x88bc30) at 0x8c3128
  REFCNT = 1
  FLAGS = (PADMY,POK,pPOK)
  PV = 0x8f2f50 "b"\0
  CUR = 1
  LEN = 8