如何使用Ruby的net::ssh库获得退出状态?

我发现下面使用net::ssh运行进程的方法更有用。它为你提供了独特的 stdout 和 stderr , exit code 和 exit signal .

require 'rubygems'
require 'net/ssh'
require 'etc'

server = 'localhost'

def ssh_exec!(ssh, command)
  stdout_data = ""
  stderr_data = ""
  exit_code = nil
  exit_signal = nil
  ssh.open_channel do |channel|
    channel.exec(command) do |ch, success|
      unless success
        abort "FAILED: couldn't execute command (ssh.channel.exec)"
      end
      channel.on_data do |ch,data|
        stdout_data+=data
      end

      channel.on_extended_data do |ch,type,data|
        stderr_data+=data
      end

      channel.on_request("exit-status") do |ch,data|
        exit_code = data.read_long
      end

      channel.on_request("exit-signal") do |ch, data|
        exit_signal = data.read_long
      end
    end
  end
  ssh.loop
  [stdout_data, stderr_data, exit_code, exit_signal]
end

Net::SSH.start(server, Etc.getlogin) do |ssh|
  puts ssh_exec!(ssh, "true").inspect
  # => ["", "", 0, nil]

  puts ssh_exec!(ssh, "false").inspect  
  # => ["", "", 1, nil]

end

希望这有帮助。

基于flitzwald的答案-我已经将我的版本修补到net::ssh(Ruby1.9+)中。

class Net::SSH::Connection::Session
  class CommandFailed < StandardError
  end

  class CommandExecutionFailed < StandardError
  end

  def exec_sc!(command)
    stdout_data,stderr_data = "",""
    exit_code,exit_signal = nil,nil
    self.open_channel do |channel|
      channel.exec(command) do |_, success|
        raise CommandExecutionFailed, "Command \"#{command}\" was unable to execute" unless success

        channel.on_data do |_,data|
          stdout_data += data
        end

        channel.on_extended_data do |_,_,data|
          stderr_data += data
        end

        channel.on_request("exit-status") do |_,data|
          exit_code = data.read_long
        end

        channel.on_request("exit-signal") do |_, data|
          exit_signal = data.read_long
        end
      end
    end
    self.loop

    raise CommandFailed, "Command \"#{command}\" returned exit code #{exit_code}" unless exit_code == 0

    {
      stdout:stdout_data,
      stderr:stderr_data,
      exit_code:exit_code,
      exit_signal:exit_signal
    }
  end
end