ruby - Ruby 中的进程间信号处理

Question

我运行这个脚本:

t = fork do
  Signal.trap "INT" do
    puts "child"
    exit
  end

  sleep 10
end


Signal.trap "INT" do
  puts "parent"
  Process.kill "INT", t
  Process.waitpid t  
  exit
end

Process.waitpid t

当我按 CTRL+C 时，我得到了

$ ruby sigtest.rb 
^Cchild 
parent

您可以看到“INT”传递给了每个进程，Process.kill "INT", t 尝试杀死已经死亡的进程。有没有办法让用户 INT 信号只传递给 parent ？输出将是:

$ ruby sigtest.rb 
^Cparent
child

解决方案

规则:

• When you press ctrl+c, SIGINT is passed to whole process group.
• When you fork new process, signal handlers are not passed to new process

所以如果你想手动控制子进程信号，你必须改变进程的GID。

见

• http://corelib.rubyonrails.org/classes/Process/Sys.html#M001961
• http://ruby.runpaint.org/processes (paragraph "Options Hash")

  def system cmd
    pid = fork do
     exec cmd, {:pgroup => true}
    end

    Process.wait pid
    $?.success?
  end

  def ` cmd # `make syntax highlight happy

    readme, writeme = IO.pipe
    pid = fork do
      $stdout.reopen writeme
      readme.close
      exec cmd, {:pgroup => true}
    end

    writeme.close
    data = readme.read

    Process.wait pid

    data
  end

Answer 1

您总是可以让 child 忽略 INT 信号。