Not related to your question, but there's no need to use parentheses on your sub declaration: you're just telling Perl that no arguments are allowed, and by placing the call before the sub Perl can't check what the sub allows anyway.

If you had use warnings; Perl would have told you this:

$ perl -wE'
foo("bar");
sub foo() { 1; }
'
main::foo() called too early to check prototype at -e line 2.
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$ perl -wE'
sub foo() { 1; }
foo("bar");
'
Too many arguments for main::foo at -e line 3, near ""bar")"
Execution of -e aborted due to compilation errors.
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