如何将用户中断添加到无限循环？

Question

我有一个ruby脚本,从下面无限打印数字从1开始.如何通过终端中的"Ctrl + C"或"q"键使脚本停止无限执行？

a = 0
while( a )
  puts a
  a += 1
  # the code should quit if an interrupt of a character is given
end

通过每次迭代,都不应该询问用户输入.

Answer 1

使用Kernel.trap为Ctrl-C安装信号处理程序:

#!/usr/bin/ruby

exit_requested = false
Kernel.trap( "INT" ) { exit_requested = true }

while !exit_requested
  print "Still running...\n"
  sleep 1
end
print "Exit was requested by user\n"

Answer 2

我认为您必须在单独的线程中检查退出条件：

# check for exit condition
Thread.new do
  loop do
    exit if gets.chomp == 'q'
  end
end

a = 0
loop do
  a += 1
  puts a
  sleep 1
end

顺便说一句，您必须输入才能q<Enter>退出，因为这就是标准输入的工作原理。