Overwrite file if it already exist in flutter

Question

Is there a way to overwrite a file's content if it already exists?

For example, with the following, we write "Hello World" and follow by "Sup?". The result of the file is "Sup?o World".

File file = ...;
file.writeAsString("Hello World");
file.writeAsString("Sup?");

The closest that I find is FileMode.write or FileMode.writeOnly.

/// The file is overwritten if it already exists. The file is created 
/// if it does not already exist.

We can rename or delete the old file. But is there a better approach?

Answer 1

Why don't you simply use

File file = ...;
final buffer = StringBuffer();

buffer.write('Hello World');
buffer.write('Sup?');

file.writeAsString(buffer.toString());

Answer 2

There's an argument that you can pass in to writeAsString(); its file mode.

writeAsString(String contents, {FileMode mode = FileMode.writeOnly});

It's mentioned in the docs, that writeOnly is,

Mode for opening a file for writing only. The file is overwritten if it already exists. The file is created if it does not already exist.

file mode reference