#!/usr/bin/perl
use strict;
use warnings;
use feature 'say';

my @array = ("backup", undef, "backup");

sub backItUp {
    say "I am backing it up!" if ($_[0] eq "backup");
}

foreach my $element (@array) {
    eval {
	die if !defined $element;

	backItUp( $element );

	1;
    } or do {
	my $error = $@ || 'Unknown failure';
        warn "Could not backup - $error";
    };
}

__END__

$ perl test.pl
I am backing it up!
Could not backup - Died at test.pl line 14.
I am backing it up!