$ 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

##</code><code>##

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

##</code><code>##

$ perl -e '
    my $file = "pm_11157157_text";
    system cat => $file;
    my ($version) = do {
        open my $fh, "<", $file;
        <$fh> =~ /([0-9.]+)/;
    };
    print "Version: $version\n";
'
# CentOS Linux release 7.6.1810 (Core)
Version: 7.6.1810

##</code><code>##

$ perl -e '
    my $file = "pm_11157157_text";
    system cat => $file;
    my ($version) = do {
        open my $fh, "<", $file;
        <$fh> =~ /([0-9.]+.+$)/;
    };
    print "Version: $version\n";
'
# CentOS Linux release 7.6.1810 (Core)
Version: 7.6.1810 (Core)