function genYumInstallScript() {
   var ver = document.getElementById('version').value;
   var plat = document.getElementById('platform').value;
   var arch = document.getElementById('arch').value;
   if (!plat || plat == -1) {
      return null;
   }
   var shortver = ver.replace('.', '');
   var url = 'https://download.postgresql.org/pub/repos/yum/reporpms/' + plat + '-' + arch + '/pgdg-' + get_rpm_prefix(plat) +'-repo-latest.noarch.rpm';
   var installer = get_installer(plat);
   var setupcmd = Number(ver) < 10
      ? 'postgresql' + shortver + '-setup'
      : 'postgresql-' + shortver + '-setup';

   var lines = [];
   lines.push('# Install the repository RPM:');
   lines.push(installer + ' install ' + url);
   lines.push('');
   lines.push('# Install client tools:');
   lines.push(installer + ' install postgresql' + shortver);
   lines.push('');
   lines.push('# Optionally install the database server:');
   lines.push(installer + ' install postgresql' + shortver + '-server');
   if (disable_module_on(plat)) {
      lines.push('');
      lines.push('# Disable the built-in PostgreSQL module:');
      lines.push('dnf -qy module disable postgresql');
   }
   lines.push('');
   lines.push('# Optionally initialize the database and enable automatic start:');
   if (uses_systemd(plat)) {
      lines.push('/usr/pgsql-' + ver + '/bin/' + setupcmd + ' initdb');
      lines.push('systemctl enable postgresql-' + ver);
      lines.push('systemctl start postgresql-' + ver);
   }
   else {
      lines.push('service postgresql-' + ver + ' initdb');
      lines.push('chkconfig postgresql-' + ver + ' on');
      lines.push('service postgresql-' + ver + ' start');
   }
   return lines.join('\n') + '\n';
}

function archChanged() {
   var text = genYumInstallScript();
   $('#scriptbox').text(text || 'Select version and platform above');
   $('#scriptcopy').css('display', text ? 'block' : 'none');
}