print $f $a;
no warnings 'unopened' ;
print $f $a;
+use warnings;
+no warnings 'unopened' ;
+print $f $a;
EXPECT
print() on unopened filehandle abc at - line 4.
########
print STDIN "anc";
opendir STDIN, ".";
print STDIN "anc";
+use warnings;
+no warnings 'closed' ;
+print STDIN "anc";
EXPECT
print() on closed filehandle STDIN at - line 4.
print() on closed filehandle STDIN at - line 6.