$ perl filename 200000
via_concat:  2002091114542256876
via_anonsub: 2002091114542256876
via_posix:   2002091114542256876
via_sprintf: 2002091114542256876
Benchmark: timing 200000 iterations of via_anonsub, via_concat, via_posix, via_sprintf...
via_anonsub:  7 wallclock secs ( 5.60 usr +  0.28 sys =  5.88 CPU)
 via_concat: 21 wallclock secs (18.71 usr +  0.55 sys = 19.27 CPU)
  via_posix: 13 wallclock secs ( 9.59 usr +  0.62 sys = 10.20 CPU)
via_sprintf: 10 wallclock secs ( 6.67 usr +  0.39 sys =  7.06 CPU)