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Re: ldm-5.1.2beta1 and pqing segmentation fault.

Mike,

Thanks for the reminder, I added the changes to the code.

Robb...





On Tue, 15 Aug 2000, Michael W Dross wrote:

> 
> 
> I compiled the ldm-5.1.2beta1 on our Linux machine which is feed via a socket
> connection from our NOAAPORT system and pqing would segmentation fault when  
> you
> specify the '-P',  socket connection parameter.  We had the same problem under
> 5.0.8, thankfully Dan Vietor provided a fix. This fix also
> seems to work for ldm-5.1.2beta1.  This problem also occurs with our AIX 4.3
> machine.  Below is the fix Dan provided. Is this something
> that Unidata can work into the next ldm release?
> 
> Thanks...
> 
> Mike
> 
> ----- Forwarded by Michael W Dross/Cust/DukePower on 08/15/00 06:25 PM -----
> |--------+----------------------->
> |        |          "Dan Vietor" |
> |        |          <address@hidden|
> |        |          ys.com>      |
> |        |                       |
> |        |          12/07/99     |
> |        |          03:46 PM     |
> |        |                       |
> |--------+----------------------->
>   
> >----------------------------------------------------------------------------|
>   |                                                                           
>  |
>   |       To:     "'Robb Kambic'" <address@hidden>, Michael W        |
>   |       Dross/Cust/DukePower@DukePower                                      
>  |
>   |       cc:     address@hidden, "'support-ldm'"                  |
>   |       <address@hidden>                                       |
>   |       bcc:                                                                
>  |
>   |       Subject:     RE: LDM 5.0.8 and pqing segmentation fault.            
>  |
>   
> >----------------------------------------------------------------------------|
> 
> 
> 
> 
> 
> 
> > Currently a define flag needs to be set in the LDM compile for the P
> > option to be available. This can be done by:
> >
> > % setenv CC "cc -DNET"
> >
> > Then build the LDM from a clean distribution or one will get old
> > configuration type problems.
> 
> When I compile 5.0.8, the NET option seemed to be there by default.
> This enabled -P use.
> 
> The seg fault comes from modifying a const integer.  In pqing.c, around
> line 408:
> 
>    *((int *)&server_port) = atoi(optarg); /* cast away const */
> 
> This causes a core dump on Linux and I believe Intel Solaris as well.
> The const declaration of server_port appears to be the culprit.  If you
> remove the const declarator in feed.h/feed.c, the code runs:
> 
> extern int server_port; /* global in feed.h */
> 
> int server_port = 0; /* set in main in feed.c */
> 
> > I noticed in the man page for pqing that the P option was no longer
> > available. I don't know what this means, it appears the code is still
> > included in pqing.c but does it work?
> 
> It appeared the man pages were rather old (dated 1996) and the -P option
> wasn't there.  When you make these changes, the -P option for reading
> from a socket works great.
> 
> ________________________________________________________
> Daniel Vietor               Mail: address@hidden
> Unisys Corp                 Title: Engineer/Meteorologist
> 221 Gale Lane               Phone: 610-444-2407
> Kennett Square PA 19348     Fax: 610-444-2420
> 
> 
> 
> 

===============================================================================
Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
address@hidden             WWW: http://www.unidata.ucar.edu/
===============================================================================