Perl Anonymous Subroutine/Function error

Question

I have the following piece of code: (extremely simplified for the purposes of this question, but perfectly illustrates the problem I am having)

#!/usr/bin/perl

use strict;
use warnings;

&outer;
my $connected_sub;

sub outer {
    print "HELLO\n";

    &$connected_sub;
    $connected_sub = sub {
        print "GOODBYE\n";
    }
}

When run the program gives this output and error:

HELLO
Use of uninitialized value in subroutine entry at subTesting line 13.
Can't use string ("") as a subroutine ref while "strict refs" in use at subTesting.pl line 13.

Am I totally overlooking something here? I cannot understand or work out what the problem with this is.

Answer 1

The $connected_sub is not initializated. Try to assign to an anonymous sub:

my $connected_sub = sub {
   print "The code you need to run\n";
}

At the definition, and drop the code after the &$connected_sub call

This is the complete example modified:

#!/usr/bin/perl
use strict;
use warnings;


my $connected_sub = sub {
   print "GOODBYE\n";
};

&outer;

sub outer
{
        print "HELLO\n";
        &$connected_sub;
 }