for(i=0;i<vector.size()-1;++i)

[Service]
Restart=always

sudo systemctl status nginx
sudo pkill -f nginx
sudo systemctl status nginx

sudo apt-get install mosquitto mosquitto-clients
sudo mosquitto_passwd -c /etc/mosquitto/passwd <mqtt_user> (set passwd here)
sudo vi /etc/mosquitto/conf.d/default.conf # new file with
  allow_anonymous false # disable anonymous user
  listener 1883 0.0.0.0 # open to all IP, open to localhost by default.
  password_file /etc/mosquitto/passwd # make password work
sudo /etc/init.d/mosquitto restart

mosquitto_sub  -h localhost -u netro -P netrohome -t 'test'
mosquitto_pub -h localhost -u netro -P netrohome -t 'test' -m 'hello'

The default max open file is 1024, which may not be enough for large MQTT service, increase it to 65535
# vi /etc/systemd/system.conf
DefaultLimitNOFILE=65536:524288
sudo systemctl daemon-reexec
sudo /etc/init.d/mosquitto restart
# cat /proc/<pid>/limits should be: 
Max open files            65535                524288               files
# count the number of file opened by: 
sudo ls /proc/<pid>/fd | wc -l

lvextend -l +100%FREE /dev/mapper/ubuntu--vg-ubuntu--lv
resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv

    <ul class="navbar-nav me-auto">
      <li class="nav-item">
        <%= link_to t('cloud'), home_index_path, class:"nav-link" %>
      </li>
    </ul>

    <ul class="navbar-nav ms-auto">
      <li class="nav-item">
        <%= link_to t('cloud'), home_index_path, class:"nav-link" %>
      </li>
    </ul>

style="overflow-y:auto; max-height:80vh"

.dropdown-menu {
 overflow-y:auto; 
 max-height:80vh
}

$('yourdiv').find('form')[0].reset();

python3.8 -m venv env

./pyftmerge:#!/home/netro/codes/chao_dev/engine_py3/env/bin/python3.8
./f2py3:#!/home/netro/codes/chao_dev/engine_py3/env/bin/python3.8
./activate.fish:set -gx VIRTUAL_ENV "/home/netro/codes/chao_dev/engine_py3/env"
./activate:VIRTUAL_ENV="/home/netro/codes/chao_dev/engine_py3/env"
./hyper:#!/home/netro/codes/chao_dev/engine_py3/env/bin/python3.8
./ttx:#!/home/netro/codes/chao_dev/engine_py3/env/bin/python3.8
./pyrsa-verify:#!/home/netro/codes/chao_dev/engine_py3/env/bin/python3.8
./futurize:#!/home/netro/codes/chao_dev/engine_py3/env/bin/python3.8
./activate.csh:setenv VIRTUAL_ENV "/home/netro/codes/chao_dev/engine_py3/env"
./pyrsa-sign:#!/home/netro/codes/chao_dev/engine_py3/env/bin/python3.8
./fixup_translate_v3beta1_keywords.py:#!/home/netro/codes/chao_dev/engine_py3/env/bin/python3.8

   order = pymongo.DESCENDING if self.descending else pymongo.ASCENDING
   items = self.tb.find(cond).sort(self.uid,order).limit(self.limit)
   logging.info(f"There are {items.count()} items")
   for idx,t in enumerate(items):
      logging.info(f"Working on {idx}-th item: {t[self.uid]}")

flash[:notice] = "This message value is available in next request-response cycle"

flash.now[:notice] = "Message is available in same request-response cycle"

    # class won't work. 
    <%= form.select:status, User.statuses.keys.to_a, class:'form-control col'%> 
    # works
    <%= form.select:status, User.statuses.keys.to_a, {},class:'form-control col'%>

# Use JavaScript with ESM import maps [https://github.com/rails/importmap-rails]
gem "importmap-rails"
# remove webpacker
gem 'webpacker', '~> 4.0'

# Hotwire's SPA-like page accelerator [https://turbo.hotwired.dev]
gem "turbo-rails"

# remove
# gem 'turbolinks', '~> 5'

# Hotwire's modest JavaScript framework [https://stimulus.hotwired.dev]
gem "stimulus-rails"

     # link_to works
      <%= link_to t('destroy'), offered_path(@offered), data: {turbo_method: :delete, turbo_confirm: 'Are you sure??'} %>
    # not working, still post method. 
      <%= button_to t('destroy'), offered_path(@offered), data: {turbo_method: :delete, turbo_confirm: 'Are you sure??'} %>
    # works
      <%= button_to t('destroy'), offered_path(@offered), method: :delete, data: {turbo_confirm: 'Are you sure??'} %>
    # confirm not work
      <%= button_to t('destroy'), offered_path(@offered), method: :delete, confirm: 'Are you sure??' %>

   format.html { render :signup }  =>
   format.html { render :signup, status: :unprocessable_entity}

    format.html { flash[:error] = "ERROR" } => 
    format.html { flash[:error] = "ERROR"; redirect_to({action: :login})}

The "default" rails way to do things that I usually see is:

submit a form
redirect on success
render html on error

As such, since Turbo currently requires redirects on all forms, it's a major blocker to prevent folks switching over.

/* Sprockets config, static resources to be compiled */
//= link_tree ../images
//= link_directory ../stylesheets .css
//= link_tree ../../javascript .js
//= link_tree ../../../vendor/javascript .js

undefined method `javascript_pack_tag'
<%= javascript_pack_tag 'application', 'data-turbo-track': 'reload' %>

    <%= javascript_importmap_tags %>

  server_name server1.com www.server1.com # 没分号不行
  server_name server1.com www.server1.com; # 有分号就好了