Hey all

I am trying to use the c api to access hdfs:

#include <stdio.h>
#include <stdlib.h>

#include <string.h>
#include <assert.h>

#include <hdfs.h>

int main (int argc, char ** argv)
{
  hdfsFS fs = hdfsConnect ("default", 0);
  assert (fs);

  const char * wp = "test";
  hdfsFile wf = hdfsOpenFile (fs, wp, O_WRONLY | O_CREAT,
                              0, 0, 0);
  if (!wf)
    {
      fprintf (stderr, "Failed to open %s for writing!\n", wp);
      exit (-1);
    }

  const char * buffer = "Hello, World!";
  tSize num_written_bytes = hdfsWrite (fs, wf, (void *) buffer,
                                       strlen (buffer) + 1);
  assert (num_written_bytes);
  if (hdfsFlush (fs, wf))
    {
      fprintf (stderr, "Failed to 'flush' %s\n", wp);
      exit (-1);
    }
  hdfsCloseFile(fs, wf);

  return 0;
}

--

gcc t.c -lhdfs -lpthread -L/usr/java/default/lib/amd64/server -ljvm -Wall

But i am getting:

Environment variable CLASSPATH not set!
getJNIEnv: getGlobalJNIEnv failed
a.out: t.c:12: main: Assertion `fs' failed.
Aborted

Not sure what i need to do now to get this example working.

--Phil

Hi!,

Assuming you have a "hadoop" command available (i.e. the
$HADOOP_HOME/bin/hadoop script), try to do:

export CLASSPATH=`hadoop classpath`

And then try to run your ./a.out.

Does this help?

Also, user questions may go to [EMAIL PROTECTED]. The
[EMAIL PROTECTED] is for Apache HDFS project
developer/development discussions alone. I've moved your thread to the
proper place.

On Thu, Feb 28, 2013 at 4:59 PM, Philip Herron <[EMAIL PROTECTED]> wrote:
> Hey all
>
> I am trying to use the c api to access hdfs:
>
> #include <stdio.h>
> #include <stdlib.h>
>
> #include <string.h>
> #include <assert.h>
>
> #include <hdfs.h>
>
> int main (int argc, char ** argv)
> {
>   hdfsFS fs = hdfsConnect ("default", 0);
>   assert (fs);
>
>   const char * wp = "test";
>   hdfsFile wf = hdfsOpenFile (fs, wp, O_WRONLY | O_CREAT,
>                               0, 0, 0);
>   if (!wf)
>     {
>       fprintf (stderr, "Failed to open %s for writing!\n", wp);
>       exit (-1);
>     }
>
>   const char * buffer = "Hello, World!";
>   tSize num_written_bytes = hdfsWrite (fs, wf, (void *) buffer,
>                                        strlen (buffer) + 1);
>   assert (num_written_bytes);
>   if (hdfsFlush (fs, wf))
>     {
>       fprintf (stderr, "Failed to 'flush' %s\n", wp);
>       exit (-1);
>     }
>   hdfsCloseFile(fs, wf);
>
>   return 0;
> }
>
> --
>
> gcc t.c -lhdfs -lpthread -L/usr/java/default/lib/amd64/server -ljvm -Wall
>
> But i am getting:
>
> Environment variable CLASSPATH not set!
> getJNIEnv: getGlobalJNIEnv failed
> a.out: t.c:12: main: Assertion `fs' failed.
> Aborted
>
> Not sure what i need to do now to get this example working.
>
> --Phil

--
Harsh J