You can check yourself with prototype
From the docs:
If FUNCTION is a string starting with CORE:: , the rest is taken as a name for a Perl builtin.
If the builtin's arguments cannot be adequately expressed by a prototype (such as system), prototype returns undef, because the builtin does not really behave like a Perl function.
Otherwise, the string describing the equivalent prototype is returned.
(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery