>>699
use Data::Dumper;
sub func_A{my $H=shift(); print "func_A : $H\n"; $H={key=>'val_A'}; print "func_A : $H\n";}
sub func_B{my $H=shift(); print "func_B : $H\n"; %$H=(key=>'val_B'); print "func_B : $H\n";}

my $H={};
print "\$H : $H\n";
func_A($H);
print Dumper $H;
func_B($H);
print Dumper $H;

これで実行してみ