[GNC] Locked out of gnucash

[Derek Atkins]

HI,

On Mon, November 25, 2019 2:01 pm, David Carlson wrote:
> If I understand, Derek, you are proposing a change to GnuCash code to
> improve it's behavior.

Yes, I am proposing a small code change.  I'll note that even changing the
text of the message involves a code change, albeit a much smaller one.

> Going back to the original question, which was about the confusing wording
> of the warning, if the code is changed, should there be warnings tailored
> to each of the three cases?

I would think so, yes.

> Note: Case 1 might mean that some third party app such as a file editor
> may
> be mucking around.  Is this true?  Is it possible to test the PID to see
> if
> it is dead or alive?

I believe that there is a way to test if a process is alive by sending it
a kill(3) command and testing the return value.  Specifically (from the
kill(3) man page):

       The kill() function shall send a signal to a process or a group of
pro‐
       cesses specified by pid.  The signal to be sent is specified by sig
and
       is either one from the list given in <signal.h> or 0. If sig is 0 
(the
       null  signal),  error  checking  is performed but no signal is
actually
       sent. The null signal can be used to check the validity of pid.

So we can just run the following code to test cases #1 and #2:

    if (kill(old_pid, 0) == 0) {
        // process is still running -- possibly duplicate gnucash?
    } else {
        // no process running -- crash/bad-shutdown?
    }

-derek

-- 
       Derek Atkins                 617-623-3745
       derek at ihtfp.com             www.ihtfp.com
       Computer and Internet Security Consultant