What does “file.sync = true” do?

Question

I had a look at the docs but I can\'t seem to find the relevant part. Can anyone tell me what the call to sync is for in the following code?

fh          


        

Answer 1

Tempfile inherits from IO. From the IO.sync docs:

  ios.sync    -> true or false

------------------------------------------------------------------------------

Returns the current ``sync mode'' of ios. When sync mode is true, all
output is immediately flushed to the underlying operating system and is not
buffered by Ruby internally. See also IO#fsync.

  f = File.new("testfile")
  f.sync   #=> false