Fun Perl question

So there's me with this bit of code that's running a bit
slow. I run the
following command:

  perl -MProf
./test.pl

and then follow it with dproffpp to see the results. I'm
then left
scratching my head to work out why I've got "Unable to
open tmon.out" before
spotting my silly mistake.

The fun question is: why did the original command seem to
work?

(I've already worked out the answer, by the way, but it
might be an amusing
puzzle for somebody else.)

> So there's me with this bit of code that's running a
bit slow. I run 
> the following command:
>
>  perl -MProf
./test.pl
>
> and then follow it with dproffpp to see the results.
I'm then left
> scratching my head to work out why I've got
"Unable to open tmon.out" 
> before spotting my silly mistake.
>
> The fun question is: why did the original command seem
to work?

And 

	perl -wMProf
./test.pl

cryptically says:

	Useless use of a constant in void context.

More recent development versions of perl would give:

	Useless use of a constant (DProf) in void context.

As of perl33407, "perl -MProf
./test.pl" fails with:

	Invalid module name Prof
with -M option: contains single ':'.

Robin

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