int ascii (const unsigned char c);

int ascii_ext (const unsigned char c);

unsigned char* strip(unsigned char* str, const size_t n, int ext );


 
int ascii (const unsigned char c) 
{  
  unsigned char min = 32;   
  unsigned char max = 126;  

  if ( c>=min && c<=max ) return 1;

  return 0;
} 


 
int ascii_ext (const unsigned char c) 
{  
  unsigned char min_ext = 128;   
  unsigned char max_ext = 255;

  if ( c>=min_ext && c<=max_ext )
       return 1;

  return 0;
} 




unsigned char* strip( unsigned char* str, const size_t n, int ext) 
{ 

  unsigned char buffer[MAXBUF] = {'\0'};

  size_t i = 0;  
  size_t j = 0;  

  size_t max = (n<MAXBUF)? n : MAXBUF -1;  

  while (i < max )
    {
      if ( (ext && ascii_ext(str[i]) ) ||  (ascii(str[i]) ) )    
	{
	  buffer[j++] = str[i]; 
	}      
      i++;
    }

  memset(str, '\0', max); 

  i = 0;               

  while( i < j)
    {
      str[i] = buffer[i]; 
      i++;
    }

  str[j] = '\0';  

  return str;  
}


int main( int argc, char** argv)
{
  enum {ASCII=0, EXT=1}; 

  unsigned int seed = 134529;  

  
  unsigned char badstring[STR_SZ] = {'\0'};
  unsigned char bs_2[STR_SZ]      = {'\0'};

  unsigned char* goodstring = NULL;
  unsigned char* goodstring_ext = NULL;

  size_t i = 0;

  srand(seed); 

  fprintf(stdout,  );

  
  for (i = 0; i < STR_SZ; i++)
    {
      badstring[i] = (unsigned char) ( rand () & (unsigned char)0xFF );
      fprintf(stdout, , badstring[i] );
    }
  fprintf(stdout, );


   memcpy(bs_2, badstring, STR_SZ * sizeof(unsigned char) ); 

   goodstring_ext = strip( badstring, STR_SZ, EXT); 

   fprintf(stdout,  , goodstring_ext );

   goodstring = strip( bs_2, STR_SZ, ASCII); 

   fprintf(stdout,  , goodstring );

return 0;
}