text: #include "cgc_ctype.h"
  
  int cgc_strcasecmp(const char *s1, const char *s2)
  {
    unsigned char *_s1 = (unsigned char *)s1;
    unsigned char *_s2 = (unsigned char *)s2;
    while (*_s1 && *_s2)
      if (!(*_s1 == *_s2 || cgc_tolower(*_s1) == cgc_tolower(*_s2)))
        break;
      else
        _s1++, _s2++;
  
    return cgc_tolower(*_s1) - cgc_tolower(*_s2);
  }
  