Automattic\WPSC\Device_Detection

User_Agent_Info::is_kindle_touch │ public static │ WPSCache 1.0

Detects if the current browser is the Kindle Touch Native browser

Mozilla/5.0 (X11; U; Linux armv7l like Android; en-us) AppleWebKit/531.2+ (KHTML, like Gecko) Version/5.0 Safari/533.2+ Kindle/3.0+

Method of the class: User_Agent_Info{}

No Hooks.

Returns

true|false. true if the browser is Kindle monochrome Native browser otherwise false

Usage

$result = User_Agent_Info::is_kindle_touch( $user_agent );
$user_agent(string|null)
User agent string to check. If not provided, uses $_SERVER['HTTP_USER_AGENT'].
Default: null

User_Agent_Info::is_kindle_touch() code WPSCache 3.1.0

wp-super-cache/src/device-detection/class-user-agent-info.php 
public static function is_kindle_touch( $user_agent = null ) {
	$user_agent = self::maybe_get_user_agent_from_server( $user_agent );
	if ( empty( $user_agent ) ) {
		return false;
	}

	$agent            = strtolower( wp_unslash( $user_agent ) ); // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- This is validating.
	$pos_kindle_touch = strpos( $agent, 'kindle/3.0+' );
	if ( false !== $pos_kindle_touch && false === self::is_kindle_fire( $user_agent ) ) {
		return true;
	} else {
		return false;
	}
}