title: Cannot kill process on port 3000
body: <p>I cannot seem to figure out how to kill this process.</p>
  
  <p>I already know that i can, and have been, just running the server on a different port, but it's just annoying me that i can't figure this out. </p>
  
  <p>Below you'll see first the error i get when i try to run rails s then all of my attempts to find the PID and kill. </p>
  
  <pre><code>// ♥ rails s
  =&gt; Booting Puma
  =&gt; Rails 5.0.0.1 application starting in development on http://localhost:3000
  =&gt; Run `rails server -h` for more startup options
  Puma starting in single mode...
  * Version 3.6.2 (ruby 2.2.3-p173), codename: Sleepy Sunday Serenity
  * Min threads: 5, max threads: 5
  * Environment: development
  * Listening on tcp://localhost:3000
  Exiting
  /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/puma-3.6.2/lib/puma/binder.rb:266:in `initialize': Address already in use - bind(2) for "::1" port 3000 (Errno::EADDRINUSE)
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/puma-3.6.2/lib/puma/binder.rb:266:in `new'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/puma-3.6.2/lib/puma/binder.rb:266:in `add_tcp_listener'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/puma-3.6.2/lib/puma/binder.rb:260:in `block in add_tcp_listener'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/puma-3.6.2/lib/puma/binder.rb:259:in `each'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/puma-3.6.2/lib/puma/binder.rb:259:in `add_tcp_listener'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/puma-3.6.2/lib/puma/binder.rb:102:in `block in parse'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/puma-3.6.2/lib/puma/binder.rb:85:in `each'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/puma-3.6.2/lib/puma/binder.rb:85:in `parse'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/puma-3.6.2/lib/puma/runner.rb:133:in `load_and_bind'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/puma-3.6.2/lib/puma/single.rb:85:in `run'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/puma-3.6.2/lib/puma/launcher.rb:172:in `run'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/puma-3.6.2/lib/rack/handler/puma.rb:51:in `run'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/rack-2.0.1/lib/rack/server.rb:296:in `start'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/railties-5.0.0.1/lib/rails/commands/server.rb:79:in `start'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:90:in `block in server'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:85:in `tap'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:85:in `server'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/railties-5.0.0.1/lib/rails/commands.rb:18:in `&lt;top (required)&gt;'
      from /Users/jrogers2/Development/code/presently/bin/rails:9:in `require'
      from /Users/jrogers2/Development/code/presently/bin/rails:9:in `&lt;top (required)&gt;'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/spring-2.0.0/lib/spring/client/rails.rb:28:in `load'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/spring-2.0.0/lib/spring/client/rails.rb:28:in `call'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/spring-2.0.0/lib/spring/client/command.rb:7:in `call'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/spring-2.0.0/lib/spring/client.rb:30:in `run'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/spring-2.0.0/bin/spring:49:in `&lt;top (required)&gt;'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/spring-2.0.0/lib/spring/binstub.rb:31:in `load'
      from /Users/jrogers2/.rvm/gems/ruby-2.2.3/gems/spring-2.0.0/lib/spring/binstub.rb:31:in `&lt;top (required)&gt;'
      from /Users/jrogers2/Development/code/presently/bin/spring:14:in `require'
      from /Users/jrogers2/Development/code/presently/bin/spring:14:in `&lt;top (required)&gt;'
      from bin/rails:3:in `load'
      from bin/rails:3:in `&lt;main&gt;'
  [09:28:36] (master) presently
  // ♥ sudo lsof -n -i4TCP:3000 | grep LISTEN
  postgres 101 postgres    5u  IPv4 0x97a8cfe190b174f1      0t0  TCP *:hbci (LISTEN)
  [09:28:43] (master) presently
  // ♥ kill -9 101
  -bash: kill: (101) - Operation not permitted
  [09:28:45] (master) presently
  // ♥ ps aux | grep puma
  jrogers2         27960   0.0  0.0  2432804   1972 s000  S+    9:28AM   0:00.00 grep puma
  [09:28:58] (master) presently
  // ♥ kill -9 27960
  -bash: kill: (27960) - No such process
  [09:29:14] (master) presently
  // ♥ ps aux | grep 3000
  jrogers2         27971   0.0  0.0  2442612   1196 s000  R+    9:29AM   0:00.00 grep 3000
  [09:29:28] (master) presently
  // ♥ kill -9 27971
  -bash: kill: (27971) - No such process
  // ♥ lsof -wni tcp:3000 
  [09:32:03] (master) presently
  // ♥ lsof -i tcp:3000 
  [09:32:41] (master) presently
  // ♥ ps aux | grep rails
  jrogers2         28035   0.0  0.0  2442612   1172 s000  R+    9:34AM   0:00.00 grep rails
  [09:34:14] (master) presently
  // ♥ kill -9 28035
  -bash: kill: (28035) - No such process
  </code></pre>