[Info-vax] Job logicals linked to a process

[Chris Townley]

On 08/01/2021 22:54, Stephen Hoffman wrote:
> On 2021-01-08 22:24:33 +0000, Chris Townley said:
> 
>> Just wondering - looking at job logicals, where the LNM table is 
>> similar to LNM$JOB_81DC4940
>>
>> I was wondering how to link a process to a particular table. Looking 
>> at the the reference above, here 81DC4940, I could not see the 
>> connection until I looked at SDA, where this is shown as the JIB address.
>>
>> I cannot find this in f$getjpi (so presumably not in LIB$GETJPI or 
>> even $GETJPI
>>
>> Any thoughts on how to find/link this, or even what it is?
> 
> Ignore my previous link.
> 
> It's the job information block JIB address, in hexadecimal.
> 
> AFAIK, there's no supported means to locate the name of a process' 
> LNM$JOB, but there are hack-ish means.
> 
> Best to use your own shared logical name table, if you need to share 
> some sort of data.
> 
> This gets discussed occasionally.
> 
> https://groups.google.com/g/comp.os.vms/c/JF9CD3GsrEU/m/8PTZKpYy3FoJ
> https://groups.google.com/g/comp.os.vms/c/JvayAq2U3JU/m/C95h2FeWdPAJ
> https://groups.google.com/g/comp.os.vms/c/al6XGcd1ZUk/m/LpvPbE2ddYUJ
> https://groups.google.com/g/comp.os.vms/c/jl04QQb02IA/m/Qq4N2LPtTRYJ
> etc.
> 
> I'm skeptical about using logical names for much of what they tend to 
> get (mis)used for—pretty much anything other than a device or file or 
> file path—but others are quite fond of this approach.
> One of the more common mis-uses: configuration data is best stored in a 
> configuration file. I've used this myself as it's relatively quick and 
> easy, and have often come to regret the results.
> 
> 
It was more of a hypothetical, historical thing. I had thought of piping 
the output from SDA, but I thought there might be any easier way. Not as 
a means of sharing data, but identifying what a process was - too many 
shared usernames!

One always learns a bit!

Thanks


Chris