You can get this information from B::Deparse. 
sub a {
    print "foo\n";
}

use B::Deparse;
my $deparser = B::Deparse->new('-p');
print $deparser->coderef2text(\&a);

[download]
Update - You can get the source of the subroutine with B::Deparse I should have said. Perhaps you meant the name of the subroutine.

In reply to Re^3: Referencing a hash of hashes by imp
in thread Referencing a hash of hashes by Ronnie

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