How would I display an error during CGI application?

Perl stores numbers internally as:

1 $a='cat'; 2 $$acatches='rat'; Which is equivalent to second line.?

?!pattern means regular expression is:

Which list items of stat() returns the mode of the file?

What is a correct way to instantiate parallel processing in PERL?

Which modifier can be used when matching in Perl to ignore case?

Perl 5 defines _____ special subroutines that are executed at specific times?

Which method pops off and returns the last value of the array?

Which statement is correct about Hashes?

Which code is True of Variables-Hashes?