Re: problem accessing multiple files using fbinread

Hi Dave,

While the "SuppressClose" parameter in setfileoption does not work for
fbinread as you pointed out, your note gave me the idea to increase my
limit of file descriptors to 2048 and the ncl code now works. Still would
be nice to know how to close files using fbinread.

Thanks for your help.

Sam

> Hi Sam,
>
> Sorry I did not look closely enough at your message. The
> instructions below only
> work for NetCDF files, not binary files.
>
> In fact, it does not seem right that fbinread does not close the file
> after reading from it.
> I will look into this.
> -dave
>
>
> On Feb 13, 2009, at 1:29 PM, David Brown wrote:
>
>> Hi Sam,
>>
>> You need to use the following incantation in your script prior to
>> opening any files:
>>
>> setfileoption("nc","SuppressClose",False)
>>
>> See http://www.ncl.ucar.edu/Document/Functions/Built-in/
>> setfileoption.shtml
>>
>> Your system has a limit of 1024 open file descriptors, and
>> subtracting several descriptors that
>> NCL opens internally for the life of its execution, you are left with
>> around 1020 files that can
>> be simultaneously opened. SuppressClose defaults to True because it
>> improves performance
>> particularly when writing files, but it does need to be modified when
>> you have many files to open
>> at once.
>> -dave
>>
>>
>> On Feb 13, 2009, at 12:11 PM, Sam Iacobellis wrote:
>>
>>> Hi,
>>>
>>> I'm trying to run a simple NCL script that reads data using the
>>> fbinread
>>> function. I need to access quite a few individual files, around
>>> 1200 or
>>> so, each file for a different day of data. After reading about 1020
>>> files, the run stops and I get an error saying that fbinread could
>>> not
>>> open the file.
>>>
>>> The problem seems not to be with the individual file, but rather
>>> that it
>>> is the 1020th file that the script has tried to access. I've
>>> reordered
>>> the loop so that the files are accessed in a different order and
>>> the same
>>> problem happens for the 1020th file.
>>>
>>> My guess is that the files remain open after I read the data and
>>> there is
>>> a limit to the amount of open files. Is there a way to close the
>>> file
>>> after I am finished reading the data?
>>>
>>> Has anyone else come across this problem? I looked through the
>>> archives,
>>> but could not find any related information.
>>>
>>> Thanks for any help.
>>>
>>> Sam.
>>>
>>>
>>> _______________________________________________
>>> ncl-talk mailing list
>>> List instructions, subscriber options, unsubscribe:
>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>
>> _______________________________________________
>> ncl-talk mailing list
>> List instructions, subscriber options, unsubscribe:
>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>
>

_______________________________________________
ncl-talk mailing list
List instructions, subscriber options, unsubscribe:
http://mailman.ucar.edu/mailman/listinfo/ncl-talk
Received on Fri Feb 13 2009 - 14:20:02 MST