#!/usr/bin/perl

my $xvport = undef;
open XVINFO, "xvinfo|" or die "Couldn't start xvinfo: $!";
while (defined(my $line = <XVINFO>)) {
    $xvport = $1 if $line =~ m/^\s+port base: (\d+)$/;
}
close XVINFO;
die "No Xv port found!" unless defined $xvport;
print STDOUT $xvport, "\n";