Title: Core_Upgrader::check_files
Published: April 25, 2014
Last modified: February 24, 2026

---

# Core_Upgrader::check_files(): bool

## In this article

 * [Return](https://developer.wordpress.org/reference/classes/core_upgrader/check_files/?output_format=md#return)
 * [Source](https://developer.wordpress.org/reference/classes/core_upgrader/check_files/?output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/classes/core_upgrader/check_files/?output_format=md#related)
 * [Changelog](https://developer.wordpress.org/reference/classes/core_upgrader/check_files/?output_format=md#changelog)

[ Back to top](https://developer.wordpress.org/reference/classes/core_upgrader/check_files/?output_format=md#wp--skip-link--target)

Compares the disk file checksums against the expected checksums.

## 󠀁[Return](https://developer.wordpress.org/reference/classes/core_upgrader/check_files/?output_format=md#return)󠁿

 bool True if the checksums match, otherwise false.

## 󠀁[Source](https://developer.wordpress.org/reference/classes/core_upgrader/check_files/?output_format=md#source)󠁿

    ```php
    public function check_files() {
    	global $wp_version, $wp_local_package;

    	$checksums = get_core_checksums( $wp_version, isset( $wp_local_package ) ? $wp_local_package : 'en_US' );

    	if ( ! is_array( $checksums ) ) {
    		return false;
    	}

    	foreach ( $checksums as $file => $checksum ) {
    		// Skip files which get updated.
    		if ( str_starts_with( $file, 'wp-content' ) ) {
    			continue;
    		}
    		if ( ! file_exists( ABSPATH . $file ) || md5_file( ABSPATH . $file ) !== $checksum ) {
    			return false;
    		}
    	}

    	return true;
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-admin/includes/class-core-upgrader.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/6.9.4/src/wp-admin/includes/class-core-upgrader.php#L403)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-admin/includes/class-core-upgrader.php#L403-L423)

## 󠀁[Related](https://developer.wordpress.org/reference/classes/core_upgrader/check_files/?output_format=md#related)󠁿

| Uses | Description | 
| [get_core_checksums()](https://developer.wordpress.org/reference/functions/get_core_checksums/)`wp-admin/includes/update.php` |

Gets and caches the checksums for the given version of WordPress.

  |

| Used by | Description | 
| [Core_Upgrader::upgrade()](https://developer.wordpress.org/reference/classes/core_upgrader/upgrade/)`wp-admin/includes/class-core-upgrader.php` |

Upgrades WordPress core.

  |

## 󠀁[Changelog](https://developer.wordpress.org/reference/classes/core_upgrader/check_files/?output_format=md#changelog)󠁿

| Version | Description | 
| [3.7.0](https://developer.wordpress.org/reference/since/3.7.0/) | Introduced. |

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