sub bar { print 'woot' }

for my $thing (qw/ foo bar /){
    print "$thing :$/";
    eval{
      no strict refs;
      &{$thing}(@_);  # possibly a nasty symbolic reference
    };
    warn "You can not call $thing: $@ " if $@;
}

##</code><code>##

foo :
You can not call foo: Undefined subroutine &main::foo called at call line 7.
  at call line 9.
bar :
woot