Example: Replace file-content (stream-based), async

public static int main (string[] args) {
if (args.length != 2) {
print ("%s FILE\n", args[0]);
return 0;
}

MainLoop loop = new MainLoop ();

File file = File.new_for_commandline_arg (args[1]);
file.replace_async.begin (null, false, FileCreateFlags.NONE, Priority.DEFAULT, null, (obj, res) => {
try {
OutputStream ostream = file.replace_async.end (res);
DataOutputStream dostream = new DataOutputStream (ostream);
dostream.put_string ("new-line\n");
} catch (Error e) {
print ("Error: %s\n", e.message);
}

loop.quit ();
});

loop.run ();
return 0;
}

 valac --pkg gio-2.0 GLib.File.replace_async.vala

See: