#include <stdio.h>

struct __FILE
{
  int handle;

  /* Whatever you require here. If the only file you are using is */
  /* standard output using printf() for debugging, no file handling */
  /* is required. */
};

/* FILE is typedef’d in stdio.h. */

FILE __stdout;

int fputc(int ch, FILE *f) 
{
  /* Your implementation of fputc(). */
  return ch;
}
int ferror(FILE *f)
{
  /* Your implementation of ferror(). */
  return 0;
}
void test(void)
{
  printf("Hello world\n");
}

File 1: Re-implement any functions that require re-implementation.

#include <stdio.h>

namespace std {

  struct __FILE
  {
    int handle;

    /* Whatever you require here. If the only file you are using is */
    /* standard output using printf() for debugging, no file handling */
    /* is required. */
  };

  FILE __stdout;
  FILE __stdin;
  FILE __stderr;

  int fgetc(FILE *f)
  {
    /* Your implementation of fgetc(). */
    return 0;
  };
  int fputc(int c, FILE *stream)
  {
    /* Your implementation of fputc(). */
  }
  int ferror(FILE *stream)
  {
    /* Your implementation of ferror(). */
  }
  long int ftell(FILE *stream)
  {
    /* Your implementation of ftell(). */
  }
  int fclose(FILE *f)
  {
    /* Your implementation of fclose(). */
    return 0;
  }
  int fseek(FILE *f, long nPos, int nMode)
  {
    /* Your implementation of fseek(). */
    return 0;
  }
  int fflush(FILE *f)
  {
    /* Your implementation of fflush(). */    
    return 0;
  }
}


File 2: Print "Hello world" using your re-implemented functions.

#include <stdio.h>
#include <iostream>
using namespace std;

int main()
{
  cout << "Hello world\n";
  return 0;
}