当Sinatra无法正确运行服务器时（例如，由于端口已在使用中），阻止Sinatra显示完整回溯的正确方法是什么？
这是一个示例sinatra应用程序：
# test.rb
require 'sinatra'
require 'bundler/inline'
gemfile do
gem 'sinatra'
gem 'puma'
end
set :bind, "0.0.0.0"
set :port, 3000
get '/' do
"hello"
end
然后，用ruby test.rb运行一次，以占用端口。
然后，在另一个终端窗口中再次运行它，并显示此完整的错误回溯：
$ ruby test.rb
== Sinatra (v2.0.4) has taken the stage on 3000 for development with backup from Puma
Puma starting in single mode...
* Version 3.12.0 (ruby 2.5.0-p0), codename: Llamas in Pajamas
* Min threads: 0, max threads: 16
* Environment: development
* Listening on tcp://0.0.0.0:3000
== Someone is already performing on port 3000!
Traceback (most recent call last):
5: from /store/gems/ruby-2.5.0/gems/sinatra-2.0.4/lib/sinatra/main.rb:26:in `block in <module:Sinatra>'
4: from /store/gems/ruby-2.5.0/gems/sinatra-2.0.4/lib/sinatra/base.rb:1464:in `run!'
3: from /store/gems/ruby-2.5.0/gems/sinatra-2.0.4/lib/sinatra/base.rb:1464:in `ensure in run!'
2: from /store/gems/ruby-2.5.0/gems/sinatra-2.0.4/lib/sinatra/base.rb:1439:in `quit!'
1: from /store/gems/ruby-2.5.0/gems/puma-3.12.0/lib/puma/launcher.rb:147:in `stop'
/store/gems/ruby-2.5.0/gems/puma-3.12.0/lib/puma/single.rb:27:in `stop': undefined method `stop' for nil:NilClass (NoMethodError)
Traceback (most recent call last):
3: from /store/gems/ruby-2.5.0/gems/sinatra-2.0.4/lib/sinatra/base.rb:1545:in `block in setup_traps'
2: from /store/gems/ruby-2.5.0/gems/sinatra-2.0.4/lib/sinatra/base.rb:1439:in `quit!'
1: from /store/gems/ruby-2.5.0/gems/puma-3.12.0/lib/puma/launcher.rb:147:in `stop'
/store/gems/ruby-2.5.0/gems/puma-3.12.0/lib/puma/single.rb:27:in `stop': undefined method `stop' for nil:NilClass (NoMethodError)
由于我将其用作嵌入式服务器，所以我希望输出简单且存在Sinatra已经显示的友好错误：
== Someone is already performing on port 3000!
并避免显示回溯。
答案 0 :(得分：1)
Ruby默认情况下将错误消息输出到STDOUT。但是，如果您使用的是* nix系统，则可以执行以下操作：
ruby test.rb > /dev/null 2>&1
对于Windows，您可能可以做到
ruby test.rb > NULL
windows powershell
ruby test.rb > $null
但对于Windows，也请参见Is there a /dev/null on Windows?
但是，如果要在服务器运行时以编程方式禁止输出，则应在* nix上运行，但不能在Windows上确定
# test.rb
require 'sinatra'
require 'bundler/inline'
gemfile do
gem 'sinatra'
gem 'puma'
end
set :bind, "0.0.0.0"
set :port, 3000
get '/' do
"hello"
end
unless `ps aux | grep sinatra`.match('tcp://0.0.0.0:3000')
STDOUT.reopen('/dev/null', 'w')
STDERR.reopen('/dev/null', 'w')
end
答案 1 :(得分：1)
您可以通过在允许Sinatra和Puma接管之前尝试监听端口来测试端口是否正在使用。这不是100％有效的，因为在某些竞争条件下，您可以打开和关闭端口，但是在Sinatra / Puma完成初始化之前，需要进行一些其他过程并在同一端口上进行侦听，但是它应该适合您的用例（似乎只是一个装饰性的技巧。
将此代码插入public HingeJoint doorHinge;
public float rotatedoor = 0.0f; // Limit this value, min 0 max 120
void Update()
{
//Get the current the limit
JointLimits limits = doorHinge.limits;
//Set the limit to that copy
limits.min = 0;
limits.max = 120;
limits.bounciness = 0;
limits.bounceMinVelocity = 0;
//Apply the limit since it's a struct
doorHinge.limits = limits;
JointSpring doorSpring = doorHinge.spring;
doorSpring.targetPosition = rotatedoor;
doorHinge.spring = doorSpring;
}
中的任何位置：
test.rb从require 'socket'
include Socket::Constants
begin
# Open and close the port
socket = Socket.new(AF_INET, SOCK_STREAM, 0)
sockaddr = Socket.pack_sockaddr_in(3000, '0.0.0.0')
socket.bind(sockaddr)
socket.listen(1)
socket.close
rescue Errno::EADDRINUSE => error
# Traps the same error that is trapped by Sinatra and exits if raised
puts error.message
exit
end
开始第一个：
ruby test.rb以== Sinatra (v2.0.4) has taken the stage on 3000 for development with backup from Puma
Puma starting in single mode...
* Version 3.12.0 (ruby 2.6.0-p-1), codename: Llamas in Pajamas
* Min threads: 0, max threads: 16
* Environment: development
* Listening on tcp://0.0.0.0:3000
Use Ctrl-C to stop
开始第二个：
ruby test.rb您可以在Address already in use - bind(2) for 0.0.0.0:3000
块中将要打印的内容充实到控制台。
答案 2 :(得分：1)
这似乎是由issue with Puma修复的this PR引起的。