When I tried to run my script, I got this message. What does it mean?

A complete list of Perl's error messages and warnings with explanatory text can be found in perldiag. You can also use the splain program (distributed with Perl) to explain the error messages:

    perl program 2>diag.out
    splain [-v] [-p] diag.out

    use diagnostics;

    use diagnostics -verbose;