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Subject: how to pass a hdfs file to a c++ process
Date: Mon, 22 Aug 2011 14:57:12 -0500
Message-ID: <8953B8331AA98041B0C11DBC678AFC08AEC745@srvemail1.calpont.com>
Thread-Topic: how to pass a hdfs file to a c++ process
Thread-Index: AcxhBa7ameq59CWYTdiK0QG9HBPRyA==
From: "Zhixuan Zhu" <zzhu@calpont.com>
To: <common-dev@hadoop.apache.org>

Hi All,

I'm using hadoop-0.20.2 to try out some simple tasks. I asked a question
about FileInputFormat a few days ago and get some prompt replys from
this forum and it helped a lot. Thanks again! Now I have another
question. I'm trying to invoke a C++ process from my mapper for each
hdfs file in the input directory to achieve some parallel processing.
But how do I pass the file to the program? I would want to do something
like the following in my mapper:

Process lChldProc =3D Runtime.getRuntime().exec("myprocess -file
$filepath");

How do I pass the hdfs filesystem to an outside process like that? Is
HadoopStreaming the direction I should go?

Thanks very much for any reply in advance.

Best,
Grace