<form method="POST">
    <h3>Editing: site-settings.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php
/**
 * Edit Site Settings Administration Screen
 *
 * @package WordPress
 * @subpackage Multisite
 * @since 3.1.0
 */

/** Load WordPress Administration Bootstrap */
require_once __DIR__ . '/admin.php';

if ( ! current_user_can( 'manage_sites' ) ) {
	wp_die( __( 'Sorry, you are not allowed to edit this site.' ) );
}

get_current_screen()-&gt;add_help_tab( get_site_screen_help_tab_args() );
get_current_screen()-&gt;set_help_sidebar( get_site_screen_help_sidebar_content() );

$id = isset( $_REQUEST['id'] ) ? (int) $_REQUEST['id'] : 0;

if ( ! $id ) {
	wp_die( __( 'Invalid site ID.' ) );
}

$details = get_site( $id );
if ( ! $details ) {
	wp_die( __( 'The requested site does not exist.' ) );
}

if ( ! can_edit_network( $details-&gt;site_id ) ) {
	wp_die( __( 'Sorry, you are not allowed to access this page.' ), 403 );
}

$is_main_site = is_main_site( $id );

if ( isset( $_REQUEST['action'] ) &amp;&amp; 'update-site' === $_REQUEST['action'] &amp;&amp; is_array( $_POST['option'] ) ) {
	check_admin_referer( 'edit-site' );

	switch_to_blog( $id );

	$skip_options = array( 'allowedthemes' ); // Don't update these options since they are handled elsewhere in the form.
	foreach ( (array) $_POST['option'] as $key =&gt; $val ) {
		$key = wp_unslash( $key );
		$val = wp_unslash( $val );
		if ( 0 === $key || is_array( $val ) || in_array( $key, $skip_options, true ) ) {
			continue; // Avoids &quot;0 is a protected WP option and may not be modified&quot; error when editing blog options.
		}
		update_option( $key, $val );
	}

	/**
	 * Fires after the site options are updated.
	 *
	 * @since 3.0.0
	 * @since 4.4.0 Added `$id` parameter.
	 *
	 * @param int $id The ID of the site being updated.
	 */
	do_action( 'wpmu_update_blog_options', $id );

	restore_current_blog();
	wp_redirect(
		add_query_arg(
			array(
				'update' =&gt; 'updated',
				'id'     =&gt; $id,
			),
			'site-settings.php'
		)
	);
	exit;
}

if ( isset( $_GET['update'] ) ) {
	$messages = array();
	if ( 'updated' === $_GET['update'] ) {
		$messages[] = __( 'Site options updated.' );
	}
}

// Used in the HTML title tag.
/* translators: %s: Site title. */
$title = sprintf( __( 'Edit Site: %s' ), esc_html( $details-&gt;blogname ) );

$parent_file  = 'sites.php';
$submenu_file = 'sites.php';

require_once ABSPATH . 'wp-admin/admin-header.php';

?&gt;

&lt;div class=&quot;wrap&quot;&gt;
&lt;h1 id=&quot;edit-site&quot;&gt;&lt;?php echo $title; ?&gt;&lt;/h1&gt;
&lt;p class=&quot;edit-site-actions&quot;&gt;&lt;a href=&quot;&lt;?php echo esc_url( get_home_url( $id, '/' ) ); ?&gt;&quot;&gt;&lt;?php _e( 'Visit' ); ?&gt;&lt;/a&gt; | &lt;a href=&quot;&lt;?php echo esc_url( get_admin_url( $id ) ); ?&gt;&quot;&gt;&lt;?php _e( 'Dashboard' ); ?&gt;&lt;/a&gt;&lt;/p&gt;

&lt;?php

network_edit_site_nav(
	array(
		'blog_id'  =&gt; $id,
		'selected' =&gt; 'site-settings',
	)
);

if ( ! empty( $messages ) ) {
	$notice_args = array(
		'type'        =&gt; 'success',
		'dismissible' =&gt; true,
		'id'          =&gt; 'message',
	);

	foreach ( $messages as $msg ) {
		wp_admin_notice( $msg, $notice_args );
	}
}
?&gt;
&lt;form method=&quot;post&quot; action=&quot;site-settings.php?action=update-site&quot;&gt;
	&lt;?php wp_nonce_field( 'edit-site' ); ?&gt;
	&lt;input type=&quot;hidden&quot; name=&quot;id&quot; value=&quot;&lt;?php echo esc_attr( $id ); ?&gt;&quot; /&gt;
	&lt;table class=&quot;form-table&quot; role=&quot;presentation&quot;&gt;
		&lt;?php
		$blog_prefix = $wpdb-&gt;get_blog_prefix( $id );
		$sql         = &quot;SELECT * FROM {$blog_prefix}options
			WHERE option_name NOT LIKE %s
			AND option_name NOT LIKE %s&quot;;
		$query       = $wpdb-&gt;prepare(
			$sql,
			$wpdb-&gt;esc_like( '_' ) . '%',
			'%' . $wpdb-&gt;esc_like( 'user_roles' )
		);
		$options     = $wpdb-&gt;get_results( $query );

		foreach ( $options as $option ) {
			if ( 'default_role' === $option-&gt;option_name ) {
				$editblog_default_role = $option-&gt;option_value;
			}

			$disabled = false;
			$class    = 'all-options';

			if ( is_serialized( $option-&gt;option_value ) ) {
				if ( is_serialized_string( $option-&gt;option_value ) ) {
					$option-&gt;option_value = esc_html( maybe_unserialize( $option-&gt;option_value ) );
				} else {
					$option-&gt;option_value = 'SERIALIZED DATA';
					$disabled             = true;
					$class                = 'all-options disabled';
				}
			}

			if ( str_contains( $option-&gt;option_value, &quot;\n&quot; ) ) {
				?&gt;
				&lt;tr class=&quot;form-field&quot;&gt;
					&lt;th scope=&quot;row&quot;&gt;&lt;label for=&quot;&lt;?php echo esc_attr( $option-&gt;option_name ); ?&gt;&quot; class=&quot;code&quot;&gt;&lt;?php echo esc_html( $option-&gt;option_name ); ?&gt;&lt;/label&gt;&lt;/th&gt;
					&lt;td&gt;&lt;textarea class=&quot;&lt;?php echo $class; ?&gt;&quot; rows=&quot;5&quot; cols=&quot;40&quot; name=&quot;option[&lt;?php echo esc_attr( $option-&gt;option_name ); ?&gt;]&quot; id=&quot;&lt;?php echo esc_attr( $option-&gt;option_name ); ?&gt;&quot;&lt;?php disabled( $disabled ); ?&gt;&gt;&lt;?php echo esc_textarea( $option-&gt;option_value ); ?&gt;&lt;/textarea&gt;&lt;/td&gt;
				&lt;/tr&gt;
				&lt;?php
			} else {
				?&gt;
				&lt;tr class=&quot;form-field&quot;&gt;
					&lt;th scope=&quot;row&quot;&gt;&lt;label for=&quot;&lt;?php echo esc_attr( $option-&gt;option_name ); ?&gt;&quot; class=&quot;code&quot;&gt;&lt;?php echo esc_html( $option-&gt;option_name ); ?&gt;&lt;/label&gt;&lt;/th&gt;
					&lt;?php if ( $is_main_site &amp;&amp; in_array( $option-&gt;option_name, array( 'siteurl', 'home' ), true ) ) { ?&gt;
					&lt;td&gt;&lt;code&gt;&lt;?php echo esc_html( $option-&gt;option_value ); ?&gt;&lt;/code&gt;&lt;/td&gt;
					&lt;?php } else { ?&gt;
					&lt;td&gt;&lt;input class=&quot;&lt;?php echo $class; ?&gt;&quot; name=&quot;option[&lt;?php echo esc_attr( $option-&gt;option_name ); ?&gt;]&quot; type=&quot;text&quot; id=&quot;&lt;?php echo esc_attr( $option-&gt;option_name ); ?&gt;&quot; value=&quot;&lt;?php echo esc_attr( $option-&gt;option_value ); ?&gt;&quot; size=&quot;40&quot; &lt;?php disabled( $disabled ); ?&gt; /&gt;&lt;/td&gt;
					&lt;?php } ?&gt;
				&lt;/tr&gt;
				&lt;?php
			}
		} // End foreach.

		/**
		 * Fires at the end of the Edit Site form, before the submit button.
		 *
		 * @since 3.0.0
		 *
		 * @param int $id Site ID.
		 */
		do_action( 'wpmueditblogaction', $id );
		?&gt;
	&lt;/table&gt;
	&lt;?php submit_button(); ?&gt;
&lt;/form&gt;

&lt;/div&gt;
&lt;?php
require_once ABSPATH . 'wp-admin/admin-footer.php';
</textarea><br>
    <input type="submit" value="Save">
</form>