URL 형식 인코딩 및 디코딩

char* urlencode(const void* buf, size_t size) {

  _assert_(buf && size <= MEMMAXSIZ);

  const unsigned char* rp = (const unsigned char*)buf;

  char* zbuf = new char[size*3+1];

  char* wp = zbuf;

  for (const unsigned char* ep = rp + size; rp < ep; rp++) {

    int32_t c = *rp;

    if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') ||

        (c >= '0' && c <= '9') || (c != '\0' && std::strchr("_-.~", c))) {

      *(wp++) = c;

    } else {

      *(wp++) = '%';

      int32_t num = c >> 4;

      if (num < 10) {

        *(wp++) = '0' + num;

      } else {

        *(wp++) = 'a' + num - 10;

      }

      num = c & 0x0f;

      if (num < 10) {

        *(wp++) = '0' + num;

      } else {

        *(wp++) = 'a' + num - 10;

      }

    }

  }

  *wp = '\0';

  return zbuf;

}

 
decode:

char* urldecode(const char* str, size_t* sp) {

  _assert_(str && sp);

  size_t zsiz = std::strlen(str);

  char* zbuf = new char[zsiz+1];

  char* wp = zbuf;

  const char* ep = str + zsiz;

  while (str < ep) {

    int32_t c = *str;

    if (c == '%') {

      int32_t num = 0;

      if (++str >= ep) break;

      c = *str;

      if (c >= '0' && c <= '9') {

        num = c - '0';

      } else if (c >= 'a' && c <= 'f') {

        num = c - 'a' + 10;

      } else if (c >= 'A' && c <= 'F') {

        num = c - 'A' + 10;

      }

      if (++str >= ep) break;

      c = *str;

      if (c >= '0' && c <= '9') {

        num = num * 0x10 + c - '0';

      } else if (c >= 'a' && c <= 'f') {

        num = num * 0x10 + c - 'a' + 10;

      } else if (c >= 'A' && c <= 'F') {

        num = num * 0x10 + c - 'A' + 10;

      }

      *(wp++) = num;

      str++;

    } else if (c == '+') {

      *(wp++) = ' ';

      str++;

    } else if (c <= ' ' || c == 0x7f) {

      str++;

    } else {

      *(wp++) = c;

      str++;

    }

  }

  *wp = '\0';

  *sp = wp - zbuf;

  return zbuf;

}