Re: Manage a ROOT file from a streaming of the ROOT file content

Of course you've to make sure the HDFS plugin is build. It is not part of the standard binary version. Get the source and make sure all prerequisite libs for HDFS support are installed and do

./configure
make

Cheers, Fons.

On 22 Apr 2012, at 09:28, Massimiliano Fasi <Massimiliano.Fasi_at_pg.infn.it> wrote:

> Hi Fons,
>
> and thank you for your explanation. I tried to use TFile::Open(), getting a different behaviour of the application. Indeed, now I get this error:
>
> Error in <TUnixSystem::DynamicPathName>: HDFS[.so | .dll | .dylib | .sl | .dl | .a] does not exist in :/storage/root/root/lib/root:/storage/root/root/lib/root:/storage/root/root/lib/root:/storage/root/root/lib/root:/storage/root/root/lib/root:/storage/root/root/lib/root:/storage/root/root/lib/root:/storage/root/root/lib/root:/storage/root/root/lib/root:/storage/root/root/lib/root:/storage/root/root/lib/root:/storage/root/root/lib/root:/storage/root/root/lib/root:/storage/root/root/lib/root:/storage/root/root/lib/root:/storage/root/root/lib/root:/storage/root/root/lib/root:.:/storage/root/root/lib/root::/storage/root/root/lib/root/cint/cint/stl
>
> [where /storage/root/root is ROOT installation directory ]
>
> It seems that now the program knows that it has to open a file stored in HDFS, even though it can't do it succesfully. Any hint on how to fix that new issue?
>
> Cheers,
> Massimiliano
>
> Fons Rademakers <Fons.Rademakers_at_cern.ch> ha scritto:
>

>> Hi,
>> 
>>  to any I/O plugin work you have to open the files via TFile::Open(), like
>> 
>> TFile* fileInput = TFile::Open(line.c_str());
>> 
>> this static method will load the HDFS plugin triggered by hdfs:// an will return a TFile derived THDFSFile object. The way you were doing it you were getting a standard local TFile object that was trying to open a local file.
>> 
>> Let me know if you've more success with TFile::Open().
>> 
>> Cheers, Fons.
>>