使用 ARGF 在 Ruby 脚本中捕获 Ctrl-D [英] Trap Ctrl-D in a Ruby Script with ARGF

问题描述

我目前正在使用 ARGV.gets 从命令行捕获用户输入.我想允许 Ctrl-D 终止脚本，但不知道如何使用 Signal.trap 或通过错误处理来执行此操作.我试图找到像 Ctrl-D 这样的陷阱代码列表，但找不到我要找的任何东西.同样，拯救 Exception 不起作用，因为 Ctrl-D 不会引发异常.是否有 Ctrl-D 的陷阱代码或任何其他检测方法?

I am currently using ARGV.gets to capture user input from the command line. I want to allow Ctrl-D terminate the script, but don't know how to do this using Signal.trap or through error handling. I tried to find a list of trap codes for something like Ctrl-D but was unable to find anything I was looking for. Likewise, rescuing Exception doesn't work because Ctrl-D doesn't raise an exception. Is there a trap code for Ctrl-D or any other way to detect this?

例如...我目前能够通过陷印来检测 Ctrl-C...

# Trap ^C 
Signal.trap("INT") { 
   # Do something 
   exit
}

或错误处理...

def get_input
   input = ARGF.gets
   input.strip!
   rescue SystemExit, Interrupt => e
   # If we get here, Ctrl-C was encountered
end

但是，我无法捕获或检测 Ctrl-D.

However, I haven't been able to trap or detect Ctrl-D.

推荐答案

ARGF 只是流的一个特例.Ctrl + D 只是输入的结尾.

ARGF in just a special case of stream. Ctrl + D is just end of input.

考虑到这一点，请使用方法 ARGF.eof?.文档链接

With this in mind use method ARGF.eof?. Link to documentation

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