What is the difference between "rb+" and "wb+"?

Question

rb+ and wb+ both read from and write to a binary file, so what makes them different?

Is it the order they read and write?

Do you mean apart from the fact that opening in read only denies being able to write? — Jon Clements, Sep 03 '18 at 11:08
@JonClements Neither of these are read-only, `+` means "open a disk file for updating (reading and writing)". — user4815162342, Sep 03 '18 at 11:17
@user4815162342 ahh... yes... of course... that's quite an embarrassing brain burp of mine :) — Jon Clements, Sep 03 '18 at 11:19

score 11 · Accepted Answer · answered Sep 03 '18 at 11:12

11

In short

there are no differences aside that.

answered Sep 03 '18 at 11:12

Zeromika

3

It's important to realize that "create the file from scratch" implies "destroy (truncate to length 0) existing one, if found". – user4815162342 Sep 03 '18 at 11:16
Oh so with `rb+` the file must already exist? – Sep 03 '18 at 11:17
1

@coder80 Indeed file must already exist while using `rb+`. – Zeromika Sep 03 '18 at 11:21
3

@coder80 Yes. Sadly, there is no mode for "use the file if it exists, create one if not". (Other than `r` and `w`, there is also `x` which is like the opposite of `r`, in that it will create the file if it doesn't exist, but it will *fail* if it exists.) – user4815162342 Sep 03 '18 at 11:29
One would think ab+ should do that, but it does not – dashesy Mar 12 '23 at 20:05

1 Answers1