I tested my original script with the

return if -d;
unlink $_
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against the golfed

unlink $_ if -f;
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and the golfed -f test seems to be a bit slower. Maybe because unlink somehow gets called for each directory then stopped? Whereas the 'return if -d ' returns immediately. BUT the improved shell with null

find . -type f -print0 | xargs -0 rm
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seems to win :-(

time -d-test Gtk3 
  real    0m0.412s
  user    0m0.074s
  sys     0m0.337s

time -f-test Gtk3 
  real    0m0.478s
  user    0m0.076s
  sys     0m0.388s

time find . -type f -print0 | xargs -0 rm
real    0m0.334s
user    0m0.012s
sys     0m0.321s
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