Method: IO#sync

Defined in:

io.c

#sync ⇒ Boolean

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

f = File.open('t.tmp', 'w')
f.sync # => false
f.sync = true
f.sync # => true
f.close

Returns:

• (Boolean)

# File 'io.c', line 2729

static VALUE
rb_io_sync(VALUE io)
{
    rb_io_t *fptr;

    io = GetWriteIO(io);
    GetOpenFile(io, fptr);
    return RBOOL(fptr->mode & FMODE_SYNC);
}