os/stdlib/stdlib.c


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char* int_to_str(int i)
{
  // Room for 4 byte int, -ve sign and null terminator
  static char buf[12];
  char *p = buf + 11;	// points to null terminator
  if (i >= 0) {
    do {
      *--p = '0' + (i % 10);
      i /= 10;
    } while (i != 0);
    return p;
  }
  else {
    do {
      *--p = '0' - (i % 10);
      i /= 10;
    } while (i != 0);
    *--p = '-';
  }
  return p;
}


int strcmp(const char *str1, const char *str2)
{
	while(*str1) {
		if (*str1 != *str2) {
	    break;
    }
		str1++;
		str2++;
	}

	return *(const unsigned char*)str1 - *(const unsigned char*)str2;
}

void strcpy(const char *src, char * dest) {
	char *ptr = dest;
	
	while (*src != '\0') {
		*dest = *src;
		dest++;
		src++;
	}
 
	*dest = '\0';
}