[nos-bbs] removing stale tty lock files

[George [ham] VerDuin]

I wonder Michael...


On 02/23/2011 10:03 AM, Michael Fox - N6MEF wrote:
>
> >>SNIP<< I stopped JNOS, manually removed the lock files, and then 
> restarted JNOS. All was well.
>
Referring to many examples on the web [including Maiko's posting], I see 
stale lock files removed prior to starting jnos. I do expect you have 
also seen this in your own work. We might see a series of statements in 
the OS start-up script like:
if [ -a file ]; then rm file; fi
where file is the whole path to the lock file that the upcoming jnos 
will establish as it opens new I/O paths. This makes the jnos feature 
redundant, and I suspect maybe it was a work-around for whatever answer 
Maiko has for your question. I'm glad you ask. I do wonder why you chose 
to skip the OS approach to removal... But that is not why I answer...

> >>SNIP<<
>
> I’ve been trying to duplicate the problem on a different machine 
> (which I have better access to) which uses USB-to-serial converters 
> (ttyUSB0, ttyUSB1, ttyUSB2).
>
RS-232 interfaces serviced by ttyS# are fully hardware dependent with 
stable numbers. USB technology is intentionally "hot pluggable" and the 
service by ttyUSB# is situational. If the devices are plugged in prior 
to OS boot time, then the # is set by the hardware service sequence and 
the same socket gets the same # each boot. But if the device is plugged 
in after boot time, then the # is assigned by the plug-in sequence 
selected by the operator no matter which socket is used. I wonder if you 
have discovered a way to sort this difference out so the ttyUSB# becomes 
stable?

In my case, I've written a document with a formula that says: "Plug the 
adapters in using the following sequence ..." where I specify BOTH the 
order of TNC/radio link and the computer socket to use. It is overly 
restrictive, but I have no better way now to set the jnos internal 
"attach" to the specific radio. It becomes hard to teach when the 
station hardware is modified from one configuration to another with a 
different radio lineup. This question IS why I answered your post.

THANKS!
Skip