wp_edit_theme_plugin_file

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Summery Summery

Attempts to edit a file for a theme or plugin.

Syntax Syntax

wp_edit_theme_plugin_file( string[] $args )

Description Description

When editing a PHP file, loopback requests will be made to the admin and the homepage to attempt to see if there is a fatal error introduced. If so, the PHP change will be reverted.

Parameters Parameters

$args

(string[]) (Required) Args. Note that all of the arg values are already unslashed. They are, however, coming straight from $_POST and are not validated or sanitized in any way.

  • 'file'
    (string) Relative path to file.
  • 'plugin'
    (string) Path to the plugin file relative to the plugins directory.
  • 'theme'
    (string) Theme being edited.
  • 'newcontent'
    (string) New content for the file.
  • 'nonce'
    (string) Nonce.

Return Return

(true|WP_Error) True on success or WP_Error on failure.

Source Source

File: wp-admin/includes/file.php

function wp_edit_theme_plugin_file( $args ) {
	if ( empty( $args['file'] ) ) {
		return new WP_Error( 'missing_file' );
	}
	$file = $args['file'];
	if ( 0 !== validate_file( $file ) ) {
		return new WP_Error( 'bad_file' );
	}

	if ( ! isset( $args['newcontent'] ) ) {
		return new WP_Error( 'missing_content' );
	}
	$content = $args['newcontent'];

	if ( ! isset( $args['nonce'] ) ) {
		return new WP_Error( 'missing_nonce' );
	}

	$plugin    = null;
	$theme     = null;
	$real_file = null;
	if ( ! empty( $args['plugin'] ) ) {
		$plugin = $args['plugin'];

		if ( ! current_user_can( 'edit_plugins' ) ) {
			return new WP_Error( 'unauthorized', __( 'Sorry, you are not allowed to edit plugins for this site.' ) );
		}

		if ( ! wp_verify_nonce( $args['nonce'], 'edit-plugin_' . $file ) ) {
			return new WP_Error( 'nonce_failure' );
		}

		if ( ! array_key_exists( $plugin, get_plugins() ) ) {
			return new WP_Error( 'invalid_plugin' );
		}

		if ( 0 !== validate_file( $file, get_plugin_files( $plugin ) ) ) {
			return new WP_Error( 'bad_plugin_file_path', __( 'Sorry, that file cannot be edited.' ) );
		}

		$editable_extensions = wp_get_plugin_file_editable_extensions( $plugin );

		$real_file = WP_PLUGIN_DIR . '/' . $file;

		$is_active = in_array(
			$plugin,
			(array) get_option( 'active_plugins', array() ),
			true
		);

	} elseif ( ! empty( $args['theme'] ) ) {
		$stylesheet = $args['theme'];
		if ( 0 !== validate_file( $stylesheet ) ) {
			return new WP_Error( 'bad_theme_path' );
		}

		if ( ! current_user_can( 'edit_themes' ) ) {
			return new WP_Error( 'unauthorized', __( 'Sorry, you are not allowed to edit templates for this site.' ) );
		}

		$theme = wp_get_theme( $stylesheet );
		if ( ! $theme->exists() ) {
			return new WP_Error( 'non_existent_theme', __( 'The requested theme does not exist.' ) );
		}

		if ( ! wp_verify_nonce( $args['nonce'], 'edit-theme_' . $stylesheet . '_' . $file ) ) {
			return new WP_Error( 'nonce_failure' );
		}

		if ( $theme->errors() && 'theme_no_stylesheet' === $theme->errors()->get_error_code() ) {
			return new WP_Error(
				'theme_no_stylesheet',
				__( 'The requested theme does not exist.' ) . ' ' . $theme->errors()->get_error_message()
			);
		}

		$editable_extensions = wp_get_theme_file_editable_extensions( $theme );

		$allowed_files = array();
		foreach ( $editable_extensions as $type ) {
			switch ( $type ) {
				case 'php':
					$allowed_files = array_merge( $allowed_files, $theme->get_files( 'php', -1 ) );
					break;
				case 'css':
					$style_files                = $theme->get_files( 'css', -1 );
					$allowed_files['style.css'] = $style_files['style.css'];
					$allowed_files              = array_merge( $allowed_files, $style_files );
					break;
				default:
					$allowed_files = array_merge( $allowed_files, $theme->get_files( $type, -1 ) );
					break;
			}
		}

		// Compare based on relative paths.
		if ( 0 !== validate_file( $file, array_keys( $allowed_files ) ) ) {
			return new WP_Error( 'disallowed_theme_file', __( 'Sorry, that file cannot be edited.' ) );
		}

		$real_file = $theme->get_stylesheet_directory() . '/' . $file;

		$is_active = ( get_stylesheet() === $stylesheet || get_template() === $stylesheet );

	} else {
		return new WP_Error( 'missing_theme_or_plugin' );
	}

	// Ensure file is real.
	if ( ! is_file( $real_file ) ) {
		return new WP_Error( 'file_does_not_exist', __( 'File does not exist! Please double check the name and try again.' ) );
	}

	// Ensure file extension is allowed.
	$extension = null;
	if ( preg_match( '/\.([^.]+)$/', $real_file, $matches ) ) {
		$extension = strtolower( $matches[1] );
		if ( ! in_array( $extension, $editable_extensions, true ) ) {
			return new WP_Error( 'illegal_file_type', __( 'Files of this type are not editable.' ) );
		}
	}

	$previous_content = file_get_contents( $real_file );

	if ( ! is_writeable( $real_file ) ) {
		return new WP_Error( 'file_not_writable' );
	}

	$f = fopen( $real_file, 'w+' );
	if ( false === $f ) {
		return new WP_Error( 'file_not_writable' );
	}

	$written = fwrite( $f, $content );
	fclose( $f );
	if ( false === $written ) {
		return new WP_Error( 'unable_to_write', __( 'Unable to write to file.' ) );
	}

	wp_opcache_invalidate( $real_file, true );

	if ( $is_active && 'php' === $extension ) {

		$scrape_key   = md5( rand() );
		$transient    = 'scrape_key_' . $scrape_key;
		$scrape_nonce = strval( rand() );
		// It shouldn't take more than 60 seconds to make the two loopback requests.
		set_transient( $transient, $scrape_nonce, 60 );

		$cookies       = wp_unslash( $_COOKIE );
		$scrape_params = array(
			'wp_scrape_key'   => $scrape_key,
			'wp_scrape_nonce' => $scrape_nonce,
		);
		$headers       = array(
			'Cache-Control' => 'no-cache',
		);

		/** This filter is documented in wp-includes/class-wp-http-streams.php */
		$sslverify = apply_filters( 'https_local_ssl_verify', false );

		// Include Basic auth in loopback requests.
		if ( isset( $_SERVER['PHP_AUTH_USER'] ) && isset( $_SERVER['PHP_AUTH_PW'] ) ) {
			$headers['Authorization'] = 'Basic ' . base64_encode( wp_unslash( $_SERVER['PHP_AUTH_USER'] ) . ':' . wp_unslash( $_SERVER['PHP_AUTH_PW'] ) );
		}

		// Make sure PHP process doesn't die before loopback requests complete.
		set_time_limit( 300 );

		// Time to wait for loopback requests to finish.
		$timeout = 100;

		$needle_start = "###### wp_scraping_result_start:$scrape_key ######";
		$needle_end   = "###### wp_scraping_result_end:$scrape_key ######";

		// Attempt loopback request to editor to see if user just whitescreened themselves.
		if ( $plugin ) {
			$url = add_query_arg( compact( 'plugin', 'file' ), admin_url( 'plugin-editor.php' ) );
		} elseif ( isset( $stylesheet ) ) {
			$url = add_query_arg(
				array(
					'theme' => $stylesheet,
					'file'  => $file,
				),
				admin_url( 'theme-editor.php' )
			);
		} else {
			$url = admin_url();
		}

		if ( function_exists( 'session_status' ) && PHP_SESSION_ACTIVE === session_status() ) {
			// Close any active session to prevent HTTP requests from timing out
			// when attempting to connect back to the site.
			session_write_close();
		}

		$url                    = add_query_arg( $scrape_params, $url );
		$r                      = wp_remote_get( $url, compact( 'cookies', 'headers', 'timeout', 'sslverify' ) );
		$body                   = wp_remote_retrieve_body( $r );
		$scrape_result_position = strpos( $body, $needle_start );

		$loopback_request_failure = array(
			'code'    => 'loopback_request_failed',
			'message' => __( 'Unable to communicate back with site to check for fatal errors, so the PHP change was reverted. You will need to upload your PHP file change by some other means, such as by using SFTP.' ),
		);
		$json_parse_failure       = array(
			'code' => 'json_parse_error',
		);

		$result = null;
		if ( false === $scrape_result_position ) {
			$result = $loopback_request_failure;
		} else {
			$error_output = substr( $body, $scrape_result_position + strlen( $needle_start ) );
			$error_output = substr( $error_output, 0, strpos( $error_output, $needle_end ) );
			$result       = json_decode( trim( $error_output ), true );
			if ( empty( $result ) ) {
				$result = $json_parse_failure;
			}
		}

		// Try making request to homepage as well to see if visitors have been whitescreened.
		if ( true === $result ) {
			$url                    = home_url( '/' );
			$url                    = add_query_arg( $scrape_params, $url );
			$r                      = wp_remote_get( $url, compact( 'cookies', 'headers', 'timeout', 'sslverify' ) );
			$body                   = wp_remote_retrieve_body( $r );
			$scrape_result_position = strpos( $body, $needle_start );

			if ( false === $scrape_result_position ) {
				$result = $loopback_request_failure;
			} else {
				$error_output = substr( $body, $scrape_result_position + strlen( $needle_start ) );
				$error_output = substr( $error_output, 0, strpos( $error_output, $needle_end ) );
				$result       = json_decode( trim( $error_output ), true );
				if ( empty( $result ) ) {
					$result = $json_parse_failure;
				}
			}
		}

		delete_transient( $transient );

		if ( true !== $result ) {

			// Roll-back file change.
			file_put_contents( $real_file, $previous_content );
			wp_opcache_invalidate( $real_file, true );

			if ( ! isset( $result['message'] ) ) {
				$message = __( 'Something went wrong.' );
			} else {
				$message = $result['message'];
				unset( $result['message'] );
			}
			return new WP_Error( 'php_error', $message, $result );
		}
	}

	if ( $theme instanceof WP_Theme ) {
		$theme->cache_delete();
	}

	return true;
}

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Changelog Changelog

Changelog
Version Description
4.9.0 Introduced.

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