sub gzip_file {
my ($file) = @_;
+ my $brotli = which 'brotli';
my $zopfli = which 'zopfli';
+ system $brotli => '--input', $file, '--output', "$file.br" if $brotli;
system $zopfli => $file if $zopfli;
gzip $file => "$file.gz", -Level => 9, Minimal => 1 unless $zopfli;
}