-3
char converte_minusculo (char *s) // porque esta errada
{
    int posicao = 0;
    while (s[posicao] != '\0')
    {
      if(s[posicao] >= 65 && s[posicao] <= 90)
        return s[posicao] + 32;
      else
          return s[posicao];
      posicao++;
    }
}
You’re not returning any value to me;
I’m not sure that’s the kind of job either.
I need you to return the converted values to the main().
If you’re not returning any value, you’re probably not entering while.
– David Alves
What was this function supposed to do? Convert a whole string into minuscule ?
– Isac