Function palaver::file::copy_fd

pub fn copy_fd(
    oldfd: RawFd, 
    newfd: RawFd, 
    flags: Option<FdFlag>, 
    allow_nonexistent: bool
) -> Result<()>

Copy a file descriptor. Flags are passed atomically. flags being None copies the flags from oldfd. Panics if newfd doesn't exist and allow_nonexistent isn't set; this can help debug the race of another thread creating newfd and having it deleted from under it by us.