$ perl -e '
    my $file = "pm_11157157_text";
    system cat => $file;
    my $version;
    {
        open my $fh, "<", $file;
        $version = (<$fh> =~ /(\d)/)[0];
    }
    print "Version: $version\n";
'
# CentOS Linux release 7.6.1810 (Core)
Version: 7