Question

I download a code example written in C, but don’t understand one instruction. And besides, w
hen i try to compile the code the compiler throws me an error just in the line that i don’t understand.

Code:

// Global vars
static int getting_text = 0;
static char *the_text;  // Definition Part
static void (*text_entered)();  // Definition Part 2


// method
int add_text(unsigned char key)
{
  char msg[] = "x";
  int len;

  if(!getting_text) return 0;
  if(key==8) /* backspace */
  {
    len = strlen(the_text);
    the_text[len-1] = '\0';
  }
  else if(key==13 || key==9) // cr or tab ends
  {
    getting_text = 0;
    text_entered(the_text); // Execution Part
  }
  else
  {
    msg[0] = key;
    strcat(the_text, msg);
  }

  glutPostRedisplay();

  return 1;
}

The compiler throws me an error about there are too many arguments in the method’s calling. But i don’t if it’s a method the static void (*xxx)() or if other thing.

Thanks in advance.

Answer 1

EDIT: The following only applies to C++. Did you use g++ or some other C++ compiler instead of a C compiler?

text_entered is a function pointer to a function that doesn’t take any arguments, hence the error, because you’re passing it a character pointer. I assume it should change to,

static void (*text_entered)(char*);

This is of course assuming text_enterered actually gets set to a function that takes a char* argument and it isn’t just being called wrong.