Sometimes it is advantageous to use code-refs.
#!/usr/bin/perl
use strict;
use warnings;
my $dref = \&new_date;
my $fref = \&new_date_append;
# call function foo, print different types of date
foo ($dref);
foo ($fref);
sub new_date {
my ( $year, $month, $day ) = (localtime)[ 5, 4, 3 ];
sprintf( "%04d%02d%02d", ( $year += 1900 ), $month + 1, $day );
}
sub new_date_append {
my $date = new_date();
return "OhioS___$date";
}
sub foo {
my $date_fn = shift;
print $date_fn->(),"\n";
}
Note
$dref=\&new_date is a reference to SUBROUTINE, $dref=\&new_date() is reference to the SCALAR returned by the subroutine