| Date: Mon, 02 Jul 2007 10:03:11 +0100
| From: Pádraig Brady <P at draigBrady.com>
| Brian Foster wrote:
| > what I'm curious about is how the ¬clocal setting is
| > being arranged? the port's NOT-open, so (I'm guessing)
| > that mysterious something must have done something to
| > arrange for ¬clocal?
| Those bits are stateful in the kernel so can be changed
| by any program/script that opens it.
thanks, Pádraig, for confirming my memory that they are
stateful. now, again, what I want to know is WHAT script
(program) is, in a SUSE 9.1 / Linux 2.6 installation,
setting the bits?
I'd assume its something in /etc/init.d/* or /etc/inittab,
but simply do not see any (plausible) candidate. maybe I'm
blind or maybe I'm looking in the wrong place, but clearly
something is setting/clearing those bits. what ???? (at
least one of the two ports is clearly not the default since
the bits differ for the two ports.)
one possibly, it occurs to me, is there's isn't any script;
instead, what I am seeing is the consequences of the last
time the modem was used (since the bits are stateful).
my (vague!) memory of archaic Unix dialout (read: UUCP) is
that's how they tended to manage it, and it clearly does
explain why I cannot find anything. it also makes a fair
amount of sense (and the idea is also clearly testable....)
( ignoring some simply debuggery at my last job, the last
time I can recall any serious serial programming was 1999,
first getting the bootstrap on a development board to talk
to a Solaris workstation, and then writing the initial
serial driver for the downloaded software. nothing too
tricky (except the UART in question had a really dumb
way of handling BREAK ;-\ ), but it _has_ been awhile,
which is perhaps why I am being a bit slow in recalling
the relevant details? )
|[ ... ]
| A general note, is serial programming is tricky.
yep! which is why I almost invariably ROTFL whenever I
see specialist serial port code. like shell scripting,
it seems almost no-one ever does a good job. (and thanks
for the references (which I haven't looked at (yet!)).)
▶ ▶ I AM CURRENTLY LOOKING FOR A JOB! ◀ ◀ | Brian Foster
Experienced (>25 yrs) software engineer: | Montpellier, FRANCE
• Unix, Linux, embedded, design-for-test; | Stop E$$o (ExxonMobile)!
• Software/hardware co-design, debugging; | http:/www.stopesso.com
• Kernels, drivers, filesystems, &tc; Résumé (CV) & contact details:
• IDL, automated testing, process, &tc. http://www.blf.utvinternet.ie
Maintained by the ILUG website team. The aim of Linux.ie is to
support and help commercial and private users of Linux in Ireland. You can
display ILUG news in your own webpages, read backend
information to find out how. Networking services kindly provided by HEAnet, server kindly donated by
Dell. Linux is a trademark of Linus Torvalds,
used with permission. No penguins were harmed in the production or maintenance
of this highly praised website. Looking for the
Indian Linux Users' Group? Try here. If you've read all this and aren't a lawyer: you should be!