WP_Filesystem() – Function | Developer.WordPress.org

Initializes and connects the WordPress Filesystem Abstraction classes.

Description

This function will include the chosen transport and attempt connecting.

Plugins may add extra transports, And force WordPress to use them by returning the filename via the ‘filesystem_method_file’ filter.

Parameters

$argsarray|falseoptional: Connection args, These are passed directly to the WP_Filesystem_*() classes.

Default:false
$contextstring|falseoptional: Context for get_filesystem_method() .

More Arguments from get_filesystem_method( … $context )
Full path to the directory that is tested for being writable.
Default:false
$allow_relaxed_file_ownershipbooloptional: Whether to allow Group/World writable.

Default:false

Return

bool|null True on success, false on failure, null if the filesystem method class file does not exist.

More Information

If no parameters are specified, the “direct” method is used. The method is determined using the get_filesystem_method() function.

One of the initial challenges for developers using the WP Filesystem API is you cannot initialize it just anywhere. The request_filesystem_credentials() function isn’t available until AFTER the wp_loaded action hook, and is only included in the admin area. One of the earliest hooks you can utilize is admin_init.

Filesystem API on Common APIs Handbook:
https://developer.wordpress.org/apis/handbook/filesystem/

Filesystem API Class Reference:
Class: WP_Filesystem_Base
Class: WP_Filesystem_Direct
Class: WP_Filesystem_FTPext
Class: WP_Filesystem_ftpsocket
Class: WP_Filesystem_SSH2

Source

function WP_Filesystem( $args = false, $context = false, $allow_relaxed_file_ownership = false ) { // phpcs:ignore WordPress.NamingConventions.ValidFunctionName.FunctionNameInvalid
	global $wp_filesystem;

	require_once ABSPATH . 'wp-admin/includes/class-wp-filesystem-base.php';

	$method = get_filesystem_method( $args, $context, $allow_relaxed_file_ownership );

	if ( ! $method ) {
		return false;
	}

	if ( ! class_exists( "WP_Filesystem_$method" ) ) {

		/**
		 * Filters the path for a specific filesystem method class file.
		 *
		 * @since 2.6.0
		 *
		 * @see get_filesystem_method()
		 *
		 * @param string $path   Path to the specific filesystem method class file.
		 * @param string $method The filesystem method to use.
		 */
		$abstraction_file = apply_filters( 'filesystem_method_file', ABSPATH . 'wp-admin/includes/class-wp-filesystem-' . $method . '.php', $method );

		if ( ! file_exists( $abstraction_file ) ) {
			return;
		}

		require_once $abstraction_file;
	}
	$method = "WP_Filesystem_$method";

	$wp_filesystem = new $method( $args );

	/*
	 * Define the timeouts for the connections. Only available after the constructor is called
	 * to allow for per-transport overriding of the default.
	 */
	if ( ! defined( 'FS_CONNECT_TIMEOUT' ) ) {
		define( 'FS_CONNECT_TIMEOUT', 30 ); // 30 seconds.
	}
	if ( ! defined( 'FS_TIMEOUT' ) ) {
		define( 'FS_TIMEOUT', 30 ); // 30 seconds.
	}

	if ( is_wp_error( $wp_filesystem->errors ) && $wp_filesystem->errors->has_errors() ) {
		return false;
	}

	if ( ! $wp_filesystem->connect() ) {
		return false; // There was an error connecting to the server.
	}

	// Set the permission constants if not already set.
	if ( ! defined( 'FS_CHMOD_DIR' ) ) {
		define( 'FS_CHMOD_DIR', ( fileperms( ABSPATH ) & 0777 | 0755 ) );
	}
	if ( ! defined( 'FS_CHMOD_FILE' ) ) {
		define( 'FS_CHMOD_FILE', ( fileperms( ABSPATH . 'index.php' ) & 0777 | 0644 ) );
	}

	return true;
}

View all references View on Trac View on GitHub

Hooks

apply_filters( ‘filesystem_method_file’, string $path, string $method ): Filters the path for a specific filesystem method class file.

Uses	Description
get_filesystem_method()`wp-admin/includes/file.php`	Determines which method to use for reading, writing, modifying, or deleting files on the filesystem.
apply_filters()`wp-includes/plugin.php`	Calls the callback functions that have been added to a filter hook.
is_wp_error()`wp-includes/load.php`	Checks whether the given variable is a WordPress Error.

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Used by	Description
_wp_delete_all_temp_backups()`wp-includes/update.php`	Deletes all contents in the temporary backup directory.
WP_Site_Health::get_test_update_temp_backup_writable()`wp-admin/includes/class-wp-site-health.php`	Tests if plugin and theme temporary backup directories are writable or can be created.
WP_Site_Health_Auto_Updates::test_all_files_writable()`wp-admin/includes/class-wp-site-health-auto-updates.php`	Checks if core files are writable by the web user/group.
wp_ajax_delete_plugin()`wp-admin/includes/ajax-actions.php`	Handles deleting a plugin via AJAX.
wp_ajax_delete_theme()`wp-admin/includes/ajax-actions.php`	Handles deleting a theme via AJAX.
WP_Upgrader::fs_connect()`wp-admin/includes/class-wp-upgrader.php`	Connects to the filesystem.
WP_Upgrader::maintenance_mode()`wp-admin/includes/class-wp-upgrader.php`	Toggles maintenance mode for the site.
delete_theme()`wp-admin/includes/theme.php`	Removes a theme.
delete_plugins()`wp-admin/includes/plugin.php`	Removes directory and files of a plugin for a list of plugins.
do_core_upgrade()`wp-admin/update-core.php`	Upgrades WordPress core display.

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Changelog

Version	Description
2.5.0	Introduced.

User Contributed Notes

Mahdi Yazdani 7 years ago

/**
 * This method gets a list of the most popular Google web fonts. 
 * Initialize the WP filesystem and no more using file_put_contents function
 *
 * @see 	wp_filesystem()
 * @see 	get_parent_theme_file_path()
 * @return 	array 	A list of Google web fonts
 */
function prefix_get_google_fonts() {

	global $wp_filesystem;

	require_once ( ABSPATH . '/wp-admin/includes/file.php' );
	WP_Filesystem();
	
	$local_file = 	get_parent_theme_file_path( '/assets/json/google-web-fonts.json' );
	$content 	= 	'';

    if ( $wp_filesystem->exists( $local_file ) ) {
        $content = json_decode( $wp_filesystem->get_contents( $local_file ) );
    } // End If Statement

	return $content;

}

This example is wrong; do not copy it. See a correct example at https://codex.wordpress.org/Filesystem_API . Specifically, this example fails to check the return value of WP_Filesystem() , and contains no provision for requesting user credentials.

David Anderson / Team Updraft 5 years ago

WP_Filesystem( array|false $args = false, string|false $context = false, bool $allow_relaxed_file_ownership = false ): bool|null

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