Retrieves metadata from a file.

Searches for metadata in the first 8 KB of a file, such as a plugin or theme.
Each piece of metadata must be on its own line. Fields can not span multiple lines, the value will get cut at the end of the first line.

If the file data is not within that first 8 KB, then the author should correct their plugin file and move the data headers to the top.

$file string Required

Absolute path to the file.

$default_headers array Required

List of headers, in the format array( 'HeaderKey' => 'Header Name' ).

$context string Optional

If specified adds filter hook 'extra_$context_headers'.

Default: ''

string[] Array of file header values keyed by header name.

File: wp-includes/functions.php. View all references

function get_file_data( $file, $default_headers, $context = '' ) {
	// Pull only the first 8 KB of the file in.
	$file_data = file_get_contents( $file, false, null, 0, 8 * KB_IN_BYTES );

	if ( false === $file_data ) {
		$file_data = '';
	}

	// Make sure we catch CR-only line endings.
	$file_data = str_replace( "\r", "\n", $file_data );

	/**
	 * Filters extra file headers by context.
	 *
	 * The dynamic portion of the hook name, `$context`, refers to
	 * the context where extra headers might be loaded.
	 *
	 * @since 2.9.0
	 *
	 * @param array $extra_context_headers Empty array by default.
	 */
	$extra_headers = $context ? apply_filters( "extra_{$context}_headers", array() ) : array();
	if ( $extra_headers ) {
		$extra_headers = array_combine( $extra_headers, $extra_headers ); // Keys equal values.
		$all_headers   = array_merge( $extra_headers, (array) $default_headers );
	} else {
		$all_headers = $default_headers;
	}

	foreach ( $all_headers as $field => $regex ) {
		if ( preg_match( '/^(?:[ \t]*<\?php)?[ \t\/*#@]*' . preg_quote( $regex, '/' ) . ':(.*)$/mi', $file_data, $match ) && $match[1] ) {
			$all_headers[ $field ] = _cleanup_header_comment( $match[1] );
		} else {
			$all_headers[ $field ] = '';
		}
	}

	return $all_headers;
}