in reply to what perl module to include to use string length function?

Welcome to the Monastery!

"global symbol requires explicit package name" is a result of "use strict;".

You can correct that by declaring the variable in question like:

my $variable;
Perl has a built-in "length" function that returns the string length. No Module is necessary.
my $length = length($variable);
There are a TON of modules - we do not refer to them as "include" modules in Perl.

These are available at CPAN.

There are also a number of modules that come pre-installed with a Perl distribution.

If you have questions with coding, it would help immensely if you posted a code sample, using <code> tags.

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