[Info-vax] Still no DIR/SORT_BY_TIME

[Johnny Billquist]

On 2015-08-17 14:50, Simon Clubley wrote:
> On 2015-08-16, Johnny Billquist <bqt at softjar.se> wrote:
>> On 2015-08-16 20:05, Simon Clubley wrote:
>>> BTW, does RSX also have a read regardless mode ?
>>
>> Not sure what you mean by that. Maybe you can explain in more detail
>> what you're asking, and then I can answer. :-)
>>
>
> With RSTS/E, when opening a file, you could specify various options
> using a mode field which was a bitfield encoded integer. Opening a file
> with mode 4096 allowed you to open and read a file when you normally be
> blocked due to an incompatible open mode from another currently running
> program.

Hmm. Essentially bypassing file locking?

> It's been a _long_ time since I last used it, but I think (IIRC) it
> could even be used to see the current contents of a file which was
> exclusively opened for writing by another program. (Assuming you had
> suitable access rights to the file of course.)

That sounds even more like bypassing file locking.

No, in RSX, if a file is locked from shared access by a program, another 
program cannot bypass that. That would defeat the point of denying 
shared access.
However, default is for programs to open files in a way that other 
programs can still access the file read-only. Only shared write access 
is by default denied. You have to explicitly open a file with shared 
write access if you really want to do that.

I should check. It might be that a privileged program can circumvent 
this, but I'm not sure.

	Johnny