See ExtUtils-Install. The perldoc for ExtUtils::Installed.pm says

 ExtUtils::Installed  provides a standard way to find out what core an
+d module files have been installed.
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try:

#!/usr/bin/perl
use ExtUtils::Installed;

my ($inst) = ExtUtils::Installed->new();
my (@modules) = $inst->modules();

foreach (@modules) {
print $_, ' v', $inst->version($_), "\n";
}
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I guess if you specify the directory to search, you can separate the Core modules out.