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mamograg17

Member

From: Kingdom of Morocco

Registered: 2022-02-08

Posts: 37

install a package using alpm

I am trying to install a package using alpm, I initialize handle, get pkg pointer from db... everything is ok,when i call alpm_trans_init() it exits with error, i don't know what is the reason, it outputs unexpected error when i output the error number.
this is my code:

alpm_errno_t err;
  alpm_handle_t * handle = alpm_initialize("/", "/var/lib/pacman", &err);

  //check for any errors
  if(!handle){
    std::cerr << "Error while initializing ALPM handle or regestring databases." << std::endl;
    return {};
  }
  //set the call back function to show progress
    alpm_option_set_dlcb(handle,(alpm_cb_download)progressCallBack,NULL);

    alpm_db_t* extra_repo = alpm_register_syncdb(handle, "extra", ALPM_DB_USAGE_INSTALL)
    if(community_repo== NULL)
    {
      std::cerr << "Error while registring sync database." << std::endl;
      alpm_release(handle);
      return 1;
    }

    alpm_pkg_t * pkg = alpm_db_get_pkg(extra_repo,"vlc");
    if(pkg == NULL)
    { 
      
      std::cerr << "Error while getting pkg from database" << std::endl;
      alpm_release(handle);
      return 1;
    }

    int trans = alpm_trans_init(handle,ALPM_TRANS_FLAG_ALLEXPLICIT); //it happens here
    if(trans == -1) {
      std::cerr << "Error while initializing transaction,reason:"<< alpm_strerror(err)  << std::endl;
      alpm_trans_release(handle);
      alpm_release(handle);
      return 1;
    }
    
    trans = alpm_add_pkg(handle,pkg);
    if(trans == -1) {
      std::cerr << "Error while adding package to transaction,reason:" << alpm_strerror(err) << std::endl;
      alpm_release(handle);
      return 1;
    }

    alpm_list_t * list = NULL;
    trans = alpm_trans_prepare(handle,&list);
    if(trans == -1) {
      std::cerr << "Error while preparing transaction" << std::endl;
      alpm_release(handle);
      return 1;
    }

    trans = alpm_trans_commit(handle,&list);
    if(trans == -1) {
      std::cerr << "Error while comming transaction" << std::endl;
      alpm_release(handle);
      return 1;
    }
  }
  

this is what if statement print:
Error while initializing transaction,reason:unexpected error