Source

File: wp-admin/includes/class-wp-filesystem-ftpsockets.php

public function dirlist( $path = '.', $include_hidden = true, $recursive = false ) {
		if ( $this->is_file( $path ) ) {
			$limit_file = basename( $path );
			$path       = dirname( $path ) . '/';
		} else {
			$limit_file = false;
		}

		mbstring_binary_safe_encoding();

		$list = $this->ftp->dirlist( $path );

		if ( empty( $list ) && ! $this->exists( $path ) ) {

			reset_mbstring_encoding();

			return false;
		}

		$ret = array();

		foreach ( $list as $struc ) {

			if ( '.' === $struc['name'] || '..' === $struc['name'] ) {
				continue;
			}

			if ( ! $include_hidden && '.' === $struc['name'][0] ) {
				continue;
			}

			if ( $limit_file && $struc['name'] != $limit_file ) {
				continue;
			}

			if ( 'd' === $struc['type'] ) {
				if ( $recursive ) {
					$struc['files'] = $this->dirlist( $path . '/' . $struc['name'], $include_hidden, $recursive );
				} else {
					$struc['files'] = array();
				}
			}

			// Replace symlinks formatted as "source -> target" with just the source name.
			if ( $struc['islink'] ) {
				$struc['name'] = preg_replace( '/(\s*->\s*.*)$/', '', $struc['name'] );
			}

			// Add the octal representation of the file permissions.
			$struc['permsn'] = $this->getnumchmodfromh( $struc['perms'] );

			$ret[ $struc['name'] ] = $struc;
		}

		reset_mbstring_encoding();

		return $ret;
	}