FileSystemEntity class Null safety

The common superclass of File, Directory, and Link.

FileSystemEntity objects are returned from directory listing operations. To determine whether a FileSystemEntity is a File, a Directory, or a Link perform a type check:

if (entity is File) (entity as File).readAsStringSync();

You can also use the type or typeSync methods to determine the type of a file system object.

Most methods in this class exist both in synchronous and asynchronous versions, for example, exists and existsSync. Unless you have a specific reason for using the synchronous version of a method, prefer the asynchronous version to avoid blocking your program.

Here's the exists method in action:

var isThere = await entity.exists();
print(isThere ? 'exists' : 'non-existent');

Other resources

• The Files and directories section of the library tour.

• Write Command-Line Apps, a tutorial about writing command-line apps, includes information about files and directories.