See the current Perl documentation for lib:subs.
Here is our local, out-dated (pre-5.6) version:
subs - Perl pragma to predeclare sub names
use subs qw(frob); frob 3..10;
This will predeclare all the subroutine whose names are in the list, allowing you to use them without parentheses even before they're declared.
Unlike pragmas that affect the
$^H hints variable, the
use vars and
use subs declarations are not BLOCK-scoped. They are thus effective for the entire
file in which they appear. You may not rescind such declarations with
no vars or