[LON-CAPA-admin] Perl Script Function "ln" supported?

Lucas, Mark lucasm at ohio.edu
Tue Nov 20 09:31:21 EST 2012

The particular problem on which this issue occurred is  


It has been used in the past without these error messages.

On capa2 and capa4 (our two library servers), I don't see any error in construction
space or in student space.

I upgraded most of my access servers to Centos 6 in the summer, but did not
mess with my library servers because of time issues. It may be that there is
a new perl library with newer releases.


On Nov 20, 2012, at 8:51 AM, Stefan Bisitz wrote:

> Hi Mark,
> Thanks for your information.
> I just talked to the LON-CAPA administrator of the domain where the 
> issue occurred "here" for the first time. He confirmed the issue, as CC 
> and AU. It's an Ubuntu Server with 64 Bit.
> Sorry to ask again: Are you sure you don't get an error message in 
> Construction Space? We get the error message on the other server and on 
> our (development) server where the function doesn't work.
> ----------------
> <problem>
> <script type="loncapa/perl">
> $a = ln(0.05);
> </script>
> <startouttext />
> a: $a
> <endouttext />
> </problem>
> ----------------
> I need to ask more:
> Do you have evidence that these problems using ln() have ever worked on 
> the machines where the error occurs now?
> From what we found in our debugging session yesterday (nothing...), we 
> still wonder where and how this function is offered by LON-CAPA anyway.
> I plan to file a bug report - especially if it can be confirmed that the 
> function should work, used to work and doesn't work anymore.
> Stefan Bisitz
> Am 19.11.2012 20:51 schrieb Lucas, Mark:
>> Stefan,
>> I was just getting ready to ask about this. We had this pop up just last night.
>> We had an instructor start getting 'bombs' on a problem that uses ln().
>> It did not get caught in construction space.
>> I just checked out a problem and I get the error messages on all our access
>> servers when I log in as a student and check out problem, but I don't get the
>> message on our library servers when I do the same thing. I also, as stated
>> above, do not get the error message in construction space (necessarily in
>> construction space).
>> What is different about perl on the library servers? One of my library servers
>> is 64-bit (Centos5.3) and the other is 32-bit (Centos 5.3).
>> Mark
>> On Nov 19, 2012, at 12:59 PM, Stefan Bisitz wrote:
>>> Hi,
>>> The perl script function "ln" (not "log" or "log10") seems to be
>>> supported by LON-CAPA, but not officially. The Script Functions help
>>> doesn't list it and it's not a perl function.
>>> The issue:
>>> Some LON-CAPA servers do not support "ln" and complain "Undefined
>>> subroutine &main::ln ..." while others calculate the correct value.
>>> So, why does it work on some servers? Should it work on all? If so, why
>>> isn't it currently?
>>> Any hints?
>>> Thanks,
>>> Stefan Bisitz
>>> _______________________________________________
>>> LON-CAPA-admin mailing list
>>> LON-CAPA-admin at mail.lon-capa.org
>>> http://mail.lon-capa.org/mailman/listinfo/lon-capa-admin
> _______________________________________________
> LON-CAPA-admin mailing list
> LON-CAPA-admin at mail.lon-capa.org
> http://mail.lon-capa.org/mailman/listinfo/lon-capa-admin

Mark Lucas 								email: lucasm at ohiou.edu
252D Clippinger Lab						phone: (740)597-2984
Department of Physics and Astronomy		fax: (740)593-0433
Ohio University
Athens, OH 45701

More information about the LON-CAPA-admin mailing list