#!/usr/bin/perl
use strict;
use warnings;
use Params::Validate qw( validate validate_pos SCALAR );

print SCALAR, "\n";
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And this one?

#!/usr/bin/perl
use strict;
use warnings;
use DateTime::Locale;

print "1\n";
[download]

When I run the first code I got following error message --
I save this code with name test.pl

Name "main::SCALAR" used only once: possible typo at test.pl line 6.
print() on unopened filehandle SCALAR at test.pl line 6.

And when I run another piece of code that time I got same error which is a subject line of this thread.

Did you copy and paste the code? Because it sounds like you missed a comma. (i.e. you have print SCALAR "\n"; in place of print SCALAR, "\n";). If not, your copy of Params::Validate was not correctly built. I just downloaded v0.95 from CPAN and have no problem, using the pure Perl version. You may wish to try downloading the tarball from http://search.cpan.org/CPAN/authors/id/D/DR/DROLSKY/Params-Validate-0.95.tar.gz, expanding it and copying Params-Validate-0.95/lib/Params/Validate.pm and Params-Validate-0.95/lib/Params/ValidatePP.pm into C:\Perl\site\lib\Params, deleting ValidateXS.pm and Validate.xs while you are there. Once this is done, try the script again.