#include <stdio_ext.h>

#include <stdlib.h>

#include <string.h>

int

main (void)

{

  FILE *fp;

  const char teststring[] = "hello world";

  char buf[3072];

  int result = 0;

  char readbuf[256];

  /* Open a file.  */

  fp = tmpfile ();

  /* Set a buffer.  */

  if (setvbuf (fp, buf, _IOFBF, sizeof buf) == EOF)

    {

      printf ("setvbuf failed: %m\n");

      exit (1);

    }

  /* Get the buffer size.  */

  if (__fbufsize (fp) != sizeof buf)

    {

      printf ("__fbusize() reported a buffer size of %Zd bytes;"

	      " we installed a buffer with %Zd bytes\n",

	      __fbufsize (fp), sizeof buf);

      result = 1;

    }

  /* Write something and read it back.  */

  if (fputs (teststring, fp) == EOF)

    {

      printf ("writing to new stream failed: %m\n");

      exit (1);

    }

  rewind (fp);

  if (fgets (readbuf, sizeof readbuf, fp) == NULL)

    {

      printf ("reading from new stream failed: %m\n");

      exit (1);

    }

  if (strcmp (readbuf, teststring) != 0)

    {

      puts ("not the correct string read");

      exit (1);

    }

  /* The file must be opened for reading and writing.  */

  if (__freading (fp) == 0)

    {

      puts ("__freading() reported stream is not last read from");

      result = 1;

    }

  if (__fwriting (fp) != 0)

    {

      puts ("__fwriting() reported stream is write-only or last written to");

      result = 1;

    }

  rewind (fp);

  if (fputs (teststring, fp) == EOF)

    {

      printf ("writing(2) to new stream failed: %m\n");

      exit (1);

    }

  if (__fwriting (fp) == 0)

    {

      puts ("__fwriting() doe snot reported stream is last written to");

      result = 1;

    }

  if (__freading (fp) != 0)

    {

      puts ("__freading() reported stream is last read from");

      result = 1;

    }

  if (__freadable (fp) == 0)

    {

      puts ("__freading() reported stream is last readable");

      result = 1;

    }

  if (__fwritable (fp) == 0)

    {

      puts ("__freading() reported stream is last writable");

      result = 1;

    }

  /* The string we wrote above should still be in the buffer.  */

  if (__fpending (fp) != strlen (teststring))

    {

      printf ("__fpending() returned %Zd; expected %Zd\n",

	      __fpending (fp), strlen (teststring));

      result = 1;

    }

  /* Discard all the output.  */

  __fpurge (fp);

  /* And check again.  */

  if (__fpending (fp) != 0)

    {

      printf ("__fpending() returned %Zd; expected 0\n",

	      __fpending (fp));

      result = 1;

    }

  /* Find out whether buffer is line buffered.  */

  if (__flbf (fp) != 0)

    {

      puts ("__flbf() reports line buffered but it is fully buffered");

      result = 1;

    }

  if (setvbuf (fp, buf, _IOLBF, sizeof buf) == EOF)

    {

      printf ("setvbuf(2) failed: %m\n");

      exit (1);

    }

  if (__flbf (fp) == 0)

    {

      puts ("__flbf() reports file is not line buffered");

      result = 1;

    }

  if (setvbuf (fp, NULL, _IONBF, 0) == EOF)

    {

      printf ("setvbuf(3) failed: %m\n");

      exit (1);

    }

  if (__flbf (fp) != 0)

    {

      puts ("__flbf() reports line buffered but it is not buffered");

      result = 1;

    }

  fclose (fp);

  return result;

}