Ubuntu/Debian 环境安装二维码库

sudo apt-get update
sudo apt-get install libqrencode-dev

Mac 环境安装二维码库

brew install qrencode

• 安装过程报权限问题执行以下命令

  sudo chown -R 用户名 /usr/local/include /usr/local/lib
  chmod u+w /usr/local/include /usr/local/lib
  

  #include 
  #include 
  #include 
  #include 
  #include 
  #include 
  void print_qr_code(QRcode *qrcode) {
      int x, y;
      for (y = 0; y < qrcode->width; y++) {
          for (x = 0; x < qrcode->width; x++) {
              // 打印二维码模块，使用 '██' 表示黑色模块，使用 '  ' 表示白色模块
              if (qrcode->data[y * qrcode->width + x] & 1) {
                  printf("██");
              } else {
                  printf("  ");
              }
          }
          printf("\n");
      }
  }
  char *get_local_ip_address() {
      struct ifaddrs *ifaddr, *ifa;
      char *ip = NULL;
      int family;
      
      if (getifaddrs(&ifaddr) == -1) {
          perror("getifaddrs");
          return NULL;
      }
      for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
          if (ifa->ifa_addr == NULL) continue;
          family = ifa->ifa_addr->sa_family;
          if (family == AF_INET) { // IPv4
              char addr[INET_ADDRSTRLEN];
              if (inet_ntop(family, &((struct sockaddr_in *)ifa->ifa_addr)->sin_addr, addr, sizeof(addr)) != NULL) {
                  // 排除回环地址和链接本地地址
                  if (strcmp(addr, "127.0.0.1") != 0 && strncmp(addr, "169.254", 7) != 0) {
                      ip = strdup(addr);
                      break;
                  }
              }
          }
      }
      freeifaddrs(ifaddr);
      return ip;
  }
  int main() {
      char *ip = get_local_ip_address();
      if (ip == NULL) {
          fprintf(stderr, "Failed to get local IP address\n");
          return 1;
      }
      // 添加 "http://" 前缀
      char url[256];
      snprintf(url, sizeof(url), "http://%s", ip);
      printf("URL: %s\n", url);
      QRcode *qrcode = QRcode_encodeString(url, 0, QR_ECLEVEL_L, QR_MODE_8, 1);
      if (qrcode == NULL) {
          fprintf(stderr, "Failed to generate QR code\n");
          free(ip);
          return 1;
      }
      print_qr_code(qrcode);
      QRcode_free(qrcode);
      free(ip);
      return 0;
  }
  

  • 编译执行

    # 编译
    gcc -o demo demo.c -L/usr/local/opt/qrencode/lib -lqrencode -I/usr/local/opt/qrencode/include
    # 执行
    ./demo
    

    • 输出结果