#include <errno.h>

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

static char fname[] = "/tmp/rndseek.XXXXXX";

static char tempdata[65 * 1024];

static int do_test (void);

#define TEST_FUNCTION do_test ()

#define TIMEOUT 10

#include "../test-skeleton.c"

static int

fp_test (const char *name, FILE *fp)

{

  int result = 0;

  int rounds = 10000;

  do

    {

      int idx = random () % (sizeof (tempdata) - 2);

      char ch1;

      char ch2;

      if (fseek (fp, idx, SEEK_SET) != 0)

	{

	  printf ("%s: %d: fseek failed: %m\n", name, rounds);

	  result = 1;

	  break;

	}

      ch1 = fgetc_unlocked (fp);

      ch2 = tempdata[idx];

      if (ch1 != ch2)

	{

	  printf ("%s: %d: character at index %d not what is expected ('%c' vs '%c')\n",

		  name, rounds, idx, ch1, ch2);

	  result = 1;

	  break;

	}

      ch1 = fgetc (fp);

      ch2 = tempdata[idx + 1];

      if (ch1 != ch2)

	{

	  printf ("%s: %d: character at index %d not what is expected ('%c' vs '%c')\n",

		  name, rounds, idx + 1, ch1, ch2);

	  result = 1;

	  break;

	}

    }

  while (--rounds > 0);

  fclose (fp);

  return result;

}

static int

do_test (void)

{

  int fd;

  FILE *fp;

  size_t i;

  int result;

  fd = mkstemp (fname);

  if (fd == -1)

    {

      printf ("cannot open temporary file: %m\n");

      return 1;

    }

  /* Make sure the file gets removed.  */

  add_temp_file (fname);

  /* Repeatability demands this.  */

  srandom (42);

  /* First create some temporary data.  */

  for (i = 0; i < sizeof (tempdata); ++i)

    tempdata[i] = 'a' + random () % 26;

  /* Write this data to a file.  */

  if (TEMP_FAILURE_RETRY (write (fd, tempdata, sizeof (tempdata)))

      != sizeof (tempdata))

    {

      printf ("cannot wrote data to temporary file: %m\n");

      return 1;

    }

  /* Now try reading the data.  */

  fp = fdopen (dup (fd), "r");

  if (fp == NULL)

    {

      printf ("cannot duplicate temporary file descriptor: %m\n");

      return 1;

    }

  rewind (fp);

  for (i = 0; i < sizeof (tempdata); ++i)

    {

      int ch0 = fgetc (fp);

      char ch1 = ch0;

      char ch2 = tempdata[i];

      if (ch0 == EOF)

	{

	  puts ("premature end of file while reading data");

	  return 1;

	}

      if (ch1 != ch2)

	{

	  printf ("%zd: '%c' vs '%c'\n", i, ch1, ch2);

	  return 1;

	}

    }

  result = fp_test ("fdopen(\"r\")", fp);

  fp = fopen (fname, "r");

  result |= fp_test ("fopen(\"r\")", fp);

  fp = fopen64 (fname, "r");

  result |= fp_test ("fopen64(\"r\")", fp);

  /* The "rw" mode will prevent the mmap-using code from being used.  */

  fp = fdopen (fd, "rw");

  result = fp_test ("fdopen(\"rw\")", fp);

  fp = fopen (fname, "rw");

  result |= fp_test ("fopen(\"rw\")", fp);

  fp = fopen64 (fname, "rw");

  result |= fp_test ("fopen64(\"rw\")", fp);

  return result;

}